Mm 


TheModernGasTractor 

ITS  CONSTRUCTION, 

OPERATION, 
^PLICATION  and  REPAIR, 


>ooocr3ooo< — >ooo< — >cxx>c >uuuerr>oooc=>i 

PRIVATE    LIBRARY 

H.  Harold  Sunderlin 

BOOK  NO. 


^otzr>ooo(==30ooc==>ooac==>oooc=)Ooo<=>oooc=}  ooocrxo 

^UL3undcrliq. 


THE 

MODERN  GAS  TRACTOR 

Its  Construction,  Utility, 
Operation  and  Repair 


A  Practical  Treatise  Defining  Every  Branch  of  Up-To- 
Date  Gas  Tractor  Engineering,  Driving  and  Mainten- 
ance in  a  Non-Technical  Manner.  Considers  Fully 
All  Types  of  Power  Plants  and  Their  Components, 
Methods  of  Drive  and  Speed  Changing  Mechanisms. 
Describes  Design  and  Construction  of  All  Parts, 
Their  Installation  and  Adjustment  As  Well  As  Prac- 
tical Application  of  Tractors  in  the  Field. 

By  VICTOR  W.  PAGE,  M.E. 

Author  of  "  The  Modern  Gasoline  Automobile  ",  etc.,  etc. 


Invaluable   to  the  Student,  Farmer,  Machinist,  Blacksmith, 

Implement  Dealer,  Rancher  and  All  Others  Wishing 

Reliable  Information  On  Gas  Motor  Propelled 

Traction  Engines  and  Their  Use 

OVER    200    ILLUSTRATIONS    AND   FOLDING   PLATES 


NEW  YORK 

THE 

NORMAN  W. 

HENLEY  PUBLISHING 

132   Nassau   Street 
1914 

COMPANY 

Copyrighted  1913   by 
THE    NORMAN    W.    HENLEY    PUBLISHING    COMPANY 


ALL     RIGHTS     RESERVED 


FIRST    IMPRESSION 


Nearly  every  illustration  in  this  book  has  been  specially  made  by 
the  publishers:    the  use  of  any  without  permission  is  prohibited 


COMPOSITION,     ELECTROTYPING    AND    PRESSWORK 
BY     MACGOWAN     &     SLIPPER,     NEW    YORK,    U.    8.    A. 


PREFACE 

The  internal  combustion  motor  has  been  responsible 
for  many  developments  in  the  industrial  sciences,  but  its 
greatest  achievement  has  been  the  promotion  of  econom- 
ical and  efficient  transportation.  The  improvements  in 
the  design  of  the  modern  gas  tractor,  which  have  made  it 
an  entirely  practical  and  satisfactory  source  of  power, 
have  also  opened  up  fields  where  it  can  be  used  to  ad- 
vantage and  profit  that  would  have  been  impossible 
with  steam  traction  engines  formerly  the  vogue,  or  other 
forms  of  power. 

It  is  not  the  writer's  intention  to  underestimate  the 
advantages  and  utility  of  the  steam  tractor;  it  has  and 
still  is  performing  work  of  great  value.  The  gas  tractor, 
however,  in  its  modern  forms,  is  able  to  accomplish 
everything  the  steam  propelled  type  can  do,  and  has 
important  advantages  the  other  construction  does  not 
possess.  It  does  not  require  services  of  a  skilled  engineer 
to  operate,  it  has  a  wider  range  of  action,  is  more  in- 
dependent of  fuel  and  water  supply  in  that  it  does  not 
consume  much  liquid  in  cooling,  and  is  more  economical 
of  fuel  because  it  utilizes  a  larger  proportion  of  the 
potential  energy  or  heat  units  of  the  combustible  by 
burning  it  directly  in  the  cylinders. 

The  many  advantages  of  the  internal  combustion 
or  gas  motor  have  made  it  the  recognized  prime  mover 
where  economical  operation  and  minimum  attendance 
is  required,  so  it  is  but  natural  that  it  should  reign  su- 
preme in  the  field  of  general  transportation. 

This  treatise  is  intended  as  a  guide  for  the  average 


x  Preface 

farmer  and  mechanic.  It  is  not  presented  as  a  technical 
or  engineering  exposition,  yet  endeavor  has  been  made 
to  present  some  principles  of  design  in  a  simple  manner 
so  they  may  be  readily  understood  by  those  without 
technical  know  edge.  The  object  of  the  writer  has  been 
to  discuss  the  engineering  features  of  various  construc- 
tions only  with  a  view  of  familiarizing  the  reader  with 
the  salient  points  of  design,  so  the  advantages  of  the 
various  systems  of  construction  may  be  intelligently 
analyzed  in  order  that  the  mechanism  best  adapted  to 
individual  requirements  be  selected. 

There  is  a  large  field  to  select  from.  Tractors  may  be 
obtained  ranging  from  motor  propelled  lawn  mowers 
or  ploughs  capable  of  use  as  light  traction  power  to 
the  heavier  constructions  employed  in  tilling  the  broad 
township  farms  of  the  Middle  West.  Special  designs 
have  been  evolved  applicable  to  use  in  swamps  or  rice 
fields  of  the  South  or  the  snow  bound  lumber  camps 
of  the  extreme  North  where  no  other  form  of  power 
can  work,  so  the  range  of  utility  of  the  gas  tractor  is 
practically  unlimited. 

The  chapters  on  maintenance  and  repair  should  be  of 
special  value,  while  the  various  applications  described 
cannot  fail  to  offer  the  up-to-date  farmer  some  suggestions 
whereby  he  can  improve  his  present  methods  and  save 
money.  The  student  is  always  interested  in  construc- 
tion and  design,  the  practical  man  wishes  more  specific 
information.  This  treatise  is  intended  to  bridge  the  gap 
existing  between  the  purely  technical  work  and  the 
manufacturers'  instruction  book  dealing  with  one 
specific  construction.  If  it  has  accomplished  this,  the 
writer  will  feel  amply  repaid  for  the  time  and  labor 
expended  on  its  compilation. 

November,  1913  THE    AUTHOR. 


ANNOUNCEMENT 

The  Author  desires  to  acknowledge  his  appreciation 
of  the  valuable  assistance  accorded  him  by  manv  of  the 
leading  firms  in  the  field  of  Tractor  Manufacture  and 
associated  industries.  Many  of  the  illustrations  have 
been  furnished  by  progressive  manufacturers  whose 
publicity  efforts  and  excellent  product  have  done  so 
much  to  popularize  the  gasoline  farm  tractor,  and  many 
valuable  suggestions  regarding  treatment  of  the  subject 
have  been  obtained  from  the  literature  so  kindly  sup- 
plied by  them.  The  following  list  of  firms  contributed 
materially  to  making  this  work  complete  and  of  value : 

Rumely  Products  Company,  La  Porte,  Ind. 

The  Gas  Tractor  Company,  Minneapolis,  Minn. 

The  Avery  Company,  Peoria,  111. 

The  Hart-Parr  Company,  Charles  City,  Iowa. 

International  Harvester  Company,  Chicago,  111. 

The  J.  I.  Case  Company,  Racine,  Wis. 

The  Bates  Tractor  Company,  Lansing,  Mich. 

Aultman  Taylor  Company,  Mansfield,  Ohio. 

Phoenix  Tractor  Company,  Winona,  Minn. 

George  Morris,  Racine,  Wis. 

Minneapolis  Steel  &  Machine  Co.,  Minneapolis,  Minn. 

Holt  Caterpillar  Co.,  Peoria,  111.,  and  New  York. 

Pioneer  Tractor  Manufacturing  Co.,  Winona,  Minn. 

Buckeye  Manufacturing  Company,  Anderson,  Ind. 

The  Russell  &  Co.,  Massillon,  Ohio. 

Auto  Tractor  Company,  Chicago,  111. 


This  Work  Is  Respectfully 
Dedicated  To  The  Backbone 
Of  Our  National  Prosperity 
THE   AMERICAN  FARMER 


xiii 


TABLE  OF  CONTEXTS 


CHAPTER  I. 

The  Scope,  Advantages  and  Applications  of  Power 
Traction. 

Influence  of  Mechanical  Power  on  the  Arts — Application  of 
Power  in  Agriculture — Advantages  of  Power  Traction — 
Comparison  Between  Work  of  Horse  and  Tractor — Thermal 
Efficiency  of  Horse — Tractor  Furnishes  Power  for  Various 
Farm  Machines — Economical  Aspect  of  Power  Traction — 
Analysis  of  Requirements  of  Ideal  Tractor — Practical 
Prime  Movers — Comparing  Steam  and  Gas  Power  from  a 
Practical  Point  of  View — Efficiency  of  Steam  and  Gas 
Power — Why  Gas  Tractors  are  Most  Popular.  33-60 

CHAPTER  II. 

Review  of  Conditions  on  Which  Tractor  Design  is 

Based. 

Elements  of  Tractor  Design  Outlined — Selection  of  Power 
Plant — Power  Needed  for  Hauling — Energy  Absorbed  by 
Ploughs — Power  Delivery  under  Belt — Why  Proper  Dis- 
tribution of  Weight  is  Essential — Influence  of  Weight  on 
Traction — Influence  of  Road  or  Field  Surface  on  Traction — 
Effect  of  Grades  on  Traction — Types  of  Tractors — Traction 
Engines  for  Small  or  Medium  Sized  Farms — Large  Capacity 
Tractors — Parts  of  Typical  Tractors  Outlined — Some 
Distinctive  Designs 61-91 

CHAPTER  III. 

Design   and   Construction   of   Gas  Tractor   Power 
Plants. 

Power  Rating  Basis — Indicated,  Brake  and  Drawbar  Horse- 
power— Types  of  Gas  Engines — Comparing  Two  and    Four 


xviii  Table  of  Contents 

CHAPTER   X. 

Traction  Engine  Troubles  and  Their  Elimination. 

Location  of  Defects  and  Remedies — Loss  of  Power — Poor 
Compression — Carbon  Deposits — Valve  Grinding — Timing 
Valves — Care  of  Piston  and  Rings — Noisy  Operation — 
Adjusting  Bearings — Mixture  Troubles — Ignition  System — 
Derangements — Cooling  and  Lubrication  Group  Faults — 
Running  Gear  Derangements — Tractor  Hitches — Utility 
and  Uses  of  Modern  Gas  Tractor — Home-made  Gas 
Tractors  —  Auto  Tractor  Attachment  —  Future  Possi- 
bilities       366-436 

CHAPTER  XI. 
Miscellaneous  Rules  and  Formulae. 

Cost  of  Various  Fuels  Per  Brake  Test  Horse-power — Rules  for 
Calculating  Horse-power — Horse-power  Formulae — Calcu- 
lating Brake  Horse-power — Anti-freezing  Solutions — Road 
Signs  of  American  Motor  League — Composition  of  Common 
Alloys — Melting  Points  of  Metals — Rust  Removers  and 
Preventives — How  to  Measure  Grades  Without  a  Grado- 
meter — Rules  and  Tables  for  Figuring  Capacity  of  Cylin- 
drical and  Rectangular  Tanks — Strength  of  Modern 
Automobile  Steels — Rule  for  Changing  Common  Fraction 
to  Decimal — Decimal  Equivalents  of  Fractions  of  an  Inch — 
Money  Conversion  Tables,  English,  French  and  German 
Coins  to  American  Values — Thermometer  Scale  Conversions 
— Metric  Conversion  Table — Revolutions  of  Various  Size 
Road  Wheels  Per  Mile — Irrigation  Tables — Horse-power 
for  Pumps — Horse-power  of  Shafts  for  Given  Diameter 
and  Speed — Horse-power  Belting  Will  Transmit — Rules  for 
Determining  Speed  of  Pulleys 437-462 


LIST  OF  ILLUSTRATIONS 


Frontispiece — The  Tractor  and  the  Plough,  an  Invincible 
Twentieth  Century  Combination. 

Fig.  1 — The  Method  of  Ploughing  in  Vogue  for  Over  5,000 

Years,  Animal  Drawn  Single  Furrow  Plough    ...      34 

Fig.  2 — The  Modern  Method  of  Soil  Tillage.  Mechanical 
Power  Furnished  by  Gas  Tractor  Pulls  Six  Ploughs  at 
Once.  Some  Tractors  Powerful  Enough  to  Make 
Fourteen  Furrows  at  a  Time 36 

Fig.  3 — A  Man  Easily  Carries  Fuel  and  Water  Enough  for  an 
Extended  Period  of  Operation  When  Gas  Engine  is 
Used  for  Power 40 

Fig.  4 — The  Caravan  Needed  to  Keep  a  Steam  Traction 
Engine  Supplied  With  Fuel  and  Water  is  a  Large  Item 
in  Operating  Costs 43 

Fig.  5 — Side  View  of  Holt  Illinois  Traction  Engine,  Showing 

Location  of  Important  Parts 46 

Fig.  6 — Typical  Large  Capacity  Gas  Tractor  of  Latest 
Approved  Design  with  Important  Parts  Clearly 
Shown 48 

Fig.  7— The  Lambert  "Steel  Hoof"  Tractor,  a  Three  Wheel 
Form  Suitable  for  Orchard  Cultivation  and  General 
Small  Farm  Work 52 

Fig.  8 — The  Wolverine  Eighteen  Horse-power  General 
Purpose  Gas  Tractor  Utilizes  Two  Cylinder  Power 
Plant 53 

Fig.  9 — The  I.  H.  C.  Twenty  Horse-power  Tractor  Utilizes 

Single  Cylinder  Engine  for  Power 58 

Fig.  10— The  Russell  Gas  Tractor  with  Four  Cylinder  Power 

Plant,  and  Single  Front  Steering  Wheel  ....      60 

Fig.    10a — Side    View    of    Phoenix    Tractor,    a    Compact 

Design 63 

Fig.   11 — Diagram  Showing  Method  of  Calculating  Grade 

Percentage 64 


xx  List  of  Illustrations 

Fig.  12 — The  Denning  Motor  Machine  Carries  a  16"  Plough 
under  Driver's  Seat  and  is  Well  Adapted  to  General 
Farm  Work 78 

Fig.  13 — The  Hackney  Auto  Plough  Carries  Three  Plough- 
shares under  Frame  and  Uses  Front  Wheels  for 
Traction 80 

Fig.   14 — The  Hackney  Auto  Plough  With  Road  Scraper 

Attachment,  a  Practical  Machine  for  Highway  Work   .     82 

Fig.  15 — Parts  of  the  Pioneer  Tractor  Outlined     ...     84 

Fig.  16 — Folding  Plate,  Side  Elevation  Holt  Caterpillar 
Tractor  Showing  all  Important  Parts  and  the  Relation 
to  Each  Other       ...  85 

Fig.  17 — Holt  Caterpillar  Tread  Tractor.  A  Distinctive 
Design  Suitable  for  Soft  Soils  or  Any  Other  Condition 
Where  Wheel  Tractors  Would  Work  at  a  Disadvantage     86 

Fig.  18 — The  Avery  Farm  Truck,  a  General  Purpose 
Machine  Powerful  Enough  for  Traction  Work  in  Field, 
Capable  of  Hauling  on  Roads  and  Its  Engine  is  Suitable 
for  Stationary  Power  if  Desired 89 

Fig.  19— An  English  Tractor  With  Three  Bottom  Gang 
Plough.  This  Machine  Driven  by  Two  Cylinder 
Vertical  Motor  Utilizes  Front  Wheels  for  Steering  and 
Traction  Duty  as  Well 90 

Fig.  20 — Simple  Diagram  to  Show  One  Method  of  Making 

a  Brake  Test  of  Small  Engine 93 

Fig.  21— Making  a  Brake  Test  in  the  Field  ...     95 

Fig.    22 — The     Kennerson     Traction     Dynamometer,     an 

Efficient  and  Simple  Instrument  for  Measuring  Draft  .     96 

Fig.  23— Sectional    View  of  Ellis  Three  Port,  Two-Cycle 

Engine,  Showing  All  Important  Parts      ....      98 

Fig.  24 — Longitudinal  Sectional  View  of  Four  -  Cycle 
Engine  of  Ohio  Tractor  With  Working  Parts  Clearly 
Indicated 100 

Fig.  25 — Views  of  Simple  Four-Cycle  Engine  Showing 
Methods  of  Charging  Cylinder  With  Explosive  Gas  and 
Compressing  It  Prior  to  Ignition 102 

Fig.  26 — Views  of  Simple  Four-Cycle  Engine  Showing 
Effect  of  Explosion  and  How  Burnt  Gases  are  Ex- 
hausted from  Cylinder 104 

Fig.  27— Defining  Action  of  Two  Port  Two-Cycle  Motor      .    107 

Fig.  28 — How  Three  Port  Two-Cycle  Engine  Operates    .         .    109 


List  of  Illustrations  xxi 

Fig.  29— Single  Cylinder  Power  Plant  Used  on  I.  H.  C.  Two 

Speed  Light  Tractor  Ill 

Fig.  30 — Diagram  Showing  Advantages  of  Multiple  Cylinder 
Motors  and  Why  They  Deliver  Power  More  Evenly 
Than  Single  Cylinder  Types .112 

Fig.  31— Fly     Wheel     Side    of    Two    Cylinder    Horizontal 

Motor  Used  in  "Oil  Pull"  Tractors 115 

Fig.  32 — Double  Opposed  Motor  of  45  Horse-power  Used  on 

I.  H.  C.  Mogul  Tractor       ...  ...    116 

Fig.  33 — Sectional  Views  of  Three  Cylinder  Vertical  Motor, 
Forming  Power  Plant  of  One  Model  of  Russell  Gas 
Tractor 118 

Fig.  34 — Sectional  Views  of  Typical  Four  Cylinder  Tractor 

Motor  That  Follows  Automobile  Practice       .        .        .    120 

Fig.  35— The  Holt  Four  Cylinder  Power  Plant  With  Valves 

Opening  Directly  into  the  Cylinder  Heads       .        .        .    122 

Fig.   36 — Four    Cylinder    Engine   Used   on   "Tiger   Pull" 

Tractors 123 

Fig.  37 — Views  of  Well  Designed  Four  Cylinder  Power 
Plant  Used  in  "Twin  City"  Gas  Tractor.  Top  View 
Shows  Water  Manifolds  and  Mechanical  Oiler;  Bottom 
View  Presents  Valve  Side  and  Shows  Induction  and 
Exhaust  Manifolds,  Carburetor  and  Magneto  .124 

Fig.  38— Single  Cylinder  Four-Cycle  Motor  With  One  Half 
of  Cylinder  and  Crankcase  Removed  to  Show  All 
Important  Parts 126 

Fig.  39— Cylinder  With  Both  Valves  on  One  Side,   Four 

Ring  Piston  and  Marine  Type  Connecting  Rod  .    130 

Fig.  40 — Sectional  View  of  "L"  Head  Cylinder  Showing 
Water  Spaces  Around  Combustion  and  Valve 
Chamber       ...........   131 

Fig.  41 — Sectional  View  of  Valve-in-Head  Vertical  Motor 
Used  on  Hart-Parr  Tractors,  Cylinder  and  Head 
Integral  .  132 

Fig.  42 — Valve-in-Head  Cylinder  Used  on  I.  H.  C.  Horizontal 

Engine  With  Separable  Head 134 

Fig.  43— Exterior  Face  of  Detachable  Cylinder  Head 
Shown  at  A  Outlines  Valve  Retention  by  Cages. 
Interior  Face  Shown  at  B  Indicates  Large  Valves 
Possible  by  This  Construction 135 


xxiv  List  of  Illustrations 

Fig.  75 — Two  Cylinder  Battery  and  Coil  Ignition  System  .  210 
Fig.  76 — Four  Cylinder  Ignition  System  Utilizing  Battery 

Current 212 

Fig.    77 — Diagram    Explaining    Action   of    Four   Cylinder 

Magneto   Ignition  System   Used  on   "Big  4-30"   Gas 

Tractor 214 

Fig.   78 — Simple   Exterior  Wiring  of  Four  Cylinder  High 

Tension  Magneto  Ignition  System 215 

Fig.  79 — Illustration  Showing  Advance  and  Retard  Positions 

of  K.  W.  Magneto  Breaker  Box 216 

Fig.   80 — Part   Sectional  View  of  Water  Jacketed   Motor 

Cylinder ...   220 

Fig.  81 — Action  of  Simple  Thermo-Syphon  Cooling  System 

Outlined ....   222 

Fig.    82 — Forced   Water    Circulation   Method    of    Cooling 

Engine  Cylinders 223 

Fig.   83 — Sectional   View  of   Hart-Parr  Horizontal   Power 

Plant  Showing  Oil  Cooling  Method.  Folding  Plate  .  225 
Fig.  84 — Simple  Form  of  Centrifugal  Pump  for  Circulating 

Cooling  Liquid 226 

Fig.  85 — Cooling  Fan  Necessary  Unless  Large  Volume  of 

Water  is  Carried 227 

Fig.  86 — Simple  Combined  Cooler  and  Water  Container  .  229 
Fig.  86A — Radiator  Used  on  Holt  Tractors  Has  Detachable 

Cooling  Sections 230 

Fig.  87— Oiling  by  Gravity  Feed  Oil  Cup  ....  235 
Fig.  88 — Sectional  View  of  Four  Cylinder  Engine  Showing 

Passages  for  Oil  Distribution  in  Crankshaft  .  .  .  237 
Fig.  89— Method  of  Supplying  Oil  Troughs  of  Holt  Tractor 

Motor  Crankcase 238 

Fig.  90 — Mechanical  Oiler  Attached  to  Motor.    Note  Leads 

to  Cylinders  and  Timing  Gear  Case  ....  239 
Fig.  91 — Sectional  View  of  Simple  Mechanical   Lubricator 

Showing  Parts 240 

Fig.    92 — Sectional    View    of    Motor    Showing    Complete 

Constant  Level  Splash  Lubricating  System  .  .  .  242 
Fig.  93 — Method   of  Lubricating  Main  Bearings  from  Oil 

Reservoirs  Integral  With  Crankcase  ....  243 
Fig.  94— Side  View  of  I.  H.  C.  Mogul  Tractor,  Showing 

Location  of  Clutch 246 


List  of  Illustrations  xxv 

Fig.  95 — Sectional  View  of  Simple  Clutch,  Showing  Principal 

Parts 249 

Fig.  96— Sectional  View  of  Master  Clutch  Used  on  Holt 

Tractors 251 

Fig.  97— Clutch  of  Avery  Tractor  is  Provided  With  Three 

Clutch  Shoes 252 

Fig.  98— Clutch  of  Rumely  Tractor  Utilizes  Three  Friction 

Shoes  Acting  on  Interior  of  Wheel  Rim  ....  253 
Fig.    99 — Side    View   of    Power   Plant   and    Friction    Disc 

Clutch  of  Heider  Tractor 255 

Fig.  100 — Explaining  Action  of  Heider  Double  Disc  Friction 

Clutch  257 

Fig.    101 — Clutch    and    Transmission    Assembly    of    Ohio 

Tractor 258 

Fig.  102 — Outlining  Action  of  Ohio  Friction  Roller  Clutch. 

A — Friction   Roller  in   Neutral   Position.      B — Roller 

in    Forward    Drive    Position.      C — Roller    Placed    to 

Obtain  Reverse  Motion 260 

Fig.    103 — Master   Clutch   and    Reversing   Mechanism    of 

Typical  Tractor    .        .        . 262 

Fig.    104 — Showing   Arrangement   of   Clutches   and   Drive 

Gears  of  Holt  Caterpillar  Tractor 264 

Fig.    105 — Diagram   Showing   Action   of   Speed   Changing 

Gearing 268 

Fig.  106 — Plan  View  of  Morris  Tractor  Mechanism,  Out- 
lining   Arrangement    of    Engine    Crankshaft,     Speed 

Changing  Mechanism  and  Rear  Axle  ....  270 
Fig.  107 — View  of  Transmission  and  Differential  Unit  With 

Cover  Removed 272 

Fig.  108— View  of  Change  Speed  Gearing  of  I.  H.  C.    Two 

Speed  Tractor  With  Sliding  Gear  in  Neutral  Position  .  273 
Fig.  109— Sliding  Gear  of  I.  H.  C.  Two  Speed  Transmission 

in  Low  Speed  Position 274 

Fig.  110 — Sliding  Gear  of  I.  H.  C.  Two  Speed  Transmission 

in  Direct  Drive  Position 275 

Fig.    Ill— Sectional   View  of  Typical   Countershaft   With 

Differential  Gear  in  Place 277 

Fig.  112— The  Differential  Spider  With  Bevel  Pinions  and 

Spur  Drive  Gear  Attached 279 

Fis.  113 — Countershaft  With  Differential  Spider  Outlined  at 

Fig.  112  Removed 280 


xxvi  List  of  Illustrations 

Fig.  114 — Frame  and  Running  Gear  Assembly  of  I.  H.  C. 

'•Mogul"  Tractor 284 

Fig.  115 — Frame  Assembly  of  Typical  Gas  Tractor,  Showing 

Driving  and  Steering  Gearing 286 

Fig.  115a— Frame  of  the  "Twin  City  40"  Gas  Tractor  Built 
of  Standard  Structural  Shapes,  Such  as  Angles  and 
Channels  Joined  Together  by  Flat  Bars  and  Braced 
by  Plates.  An  Exceptionally  Substantial  Design 
Representative  of  Best  Construction        .        .        .        .287 

Fig.  116— Rear  End  of  I.  H.  C.  Tractor  Frame,  Showing 
Substantial  Cast  Members  Serving  to  Support  Counter- 
shaft and  Rear  Axle  Bearings 2ss 

Fig.  117 — How  Pivoted  Solid  Front  Axle  Permits  Frame 
Movement  Without  Distortion  by  the  Three  Point 
Support.  A — On  Level  Ground.  Z?— Rear  Wheel 
Surmounting  an  Obstacle 289 

Fig.  118 — Showing  Arrangement  of  Ackerman  Front  Axle 

to  Obtain   Three  Point  Support  of  Tractor  Frame      .    291 

Fig.  119 — Method  of  Mounting  Front  End  of  Phoenix 
Tractor  Frame  on  Springs  Designed  to  Permit  Three 
Point  Suspension  Principle 292 

Fig.  123 — Showing  Advantages  of  Large  Wheels  for  Tractor 

Driving  Members 293 

Fig.  121 — Tractor  Driving  Wheel  Showing  Method  of 
Attaching  External  Spur  Bull  Gear  to  Wheel  Hub 
and  Rim 295 

Fig.  122 — Tractor  Driving  Wheel  and  Hub  Casting.  Note 
Internal  Spur  Drive  Gear  and  Method  of  Attaching  to 
Hub  and  Rim 297 

Fig.    123— Traction  Wheel   of   Gas   Tractor   With   Spring 

Members  to  Remove  Shocks  from  Driving  Gsars     .   298 

Fig.     124 — Driving    Wheel    of    Tractor    Utilizing    Chain 

Drive 299 

Fig.   125 — Cross  Section  of  Hart-Parr  Rear  Hub  Showing 

Wheel  Bearing  and  Method  of  Lubrication      .        .        .    300 

Fig.  126 — Traction  Wheel  Rims  Showing  Cleats  or  Grouters 
of  Various  Types  Utilized  to  Increase  Frictional 
Adhesion  With  Ground 301 

Fig.  127 — Extension  Rims  Designed  to  be  Attached  to 
Regular  Traction  Wheels  to  Obtain  Greater  Contact 
Area  When  Used  on  Soft  Ground 302 


List  op  Illustrations  xxvii 

Fig.     128 — Showing    Construction    of    Caterpillar     Tread 

Traction  Member  of  Holt  Tractor 303 

Fig.    129 — Comparison    Between    Wheel    and    Caterpillar 

Tread  Traction  Members 305 

Fig.    130 — Tabular    Comparison   Between    Caterpillar   and 

Wheel  Types  of  Traction  Engines 306 

Fig.  131 — Showing  Two  Methods  of  Steering  Four  Wheeled 
Traction  Engines.  A — Tight  and  Loose  Chain 
Method.  B — -Worm  and  Sector  Gear  and  Ackerman 
Axle 307 

Fig.   132— Front  View  of  I.  H.  C.  "Mogul"  Gas  Tractor 

Frame  Showing  Centrally  Pivoted  One  Piece  Axle      .    309 

Fig.  133— Front  View  of  I.  H.  C.  Tractor  Using  Ackerman 

Type  Front  Axle  With  Elliot  Pattern  Steering  Knuckles  310 

Fig.  134— Front  View  of  Three  Wheel  Hart-Parr  Gas 
Tractor  Frame  Utilizing  One  Wheel  for  Steering 
Purposes 312 

Fig.  135 — Sectional  View  of  Front  Wheel  of  Hart-Parr 
Three  Wheel  Tractor  Showing  Method  of  Supporting 
Steering  Member 313 

Fig.    136 — Outlining    Application    of    Automatic    Steering 

Arrangement  to '"Big  4-30"  Gas  Tractor   ....   315 

Fig.  133a— The  Cuddy  Automatic  Steering  Device  Applied 

to  Ackerman  Type  Front  Axle 316 

Fig.    137 — Showing    Important  Members  of   Conventional 

Power  Transmission  System 317 

Fig.  138 — Front  View  of  Hackney  Gas  Tractor  Which  Has 
Traction  Members  at  Front  End  and  Single  Rear 
Wheel  for  Steering 319 

Fig.  139— Rear  View  of  Holt  Caterpillar  Tractor  Showing 

Chain  Drive  to  Traction  Members  from  Cross  Shaft     .    321 

Fig.  140 — Sectional  View  of  Worm  Drive  Gearing  Used  in 

Connection  With  Live  Rear  Axle 323 

Fig.  141 — Sectional  View  of  Half  of  Rear  Axle  of  Live  Type 

Used  in  Connection  With  Worm  Gear  Final  Drive      .    324 

Fig.  142 — Side  View  of  Morris  Tractor  Showing  Operator's 

Platform  and  Control  Levers 328 

Fig.  143 — Governors  of  the  Centrifugal  Type  Form  Im- 
portant Part  of  Tractor  Power  Plant  Control  System    .   329 

Fig.  144 — Small  Engine  Used  to  Start  Large  Power  Plant 

of  I.  H.  C.  "Mogul"  Tractor 331 


xxx  List  of  Illustrations 

Fig.  176 — Ploughing,  Packing,  Harrowing  and  Seeding 
This  Ground  Accomplished  in  One  Operation.  "Twin 
City  40"  Gas  Tractor  Furnishes  Power  When  Utilized 
in  This  Manner  at  Extremely  Low  Cost    ....    407 

Fig.  177 — Outfit  of  Berland  &  Lee,  Brady,  Mont.,  Plough- 
ing With  Disc  Plough  and  Packing  With  Stone  Drag   .    408 

Fig.  17S — Simple  Three  Drill  Hitch  Easily  Made  by  Any 

Farmer  409 

Fig.  179— Wrought  Iron  Pipe  Drill  Hitch  for  Three  Drills   .   409 

Fig.  180— Practical  Application  of  Drill  Hitch       .        .        .410 

Fig.  181 — Hansmann  Patent  Five  Drill  Hitch  Very  Useful 
in  Seeding  Large  Areas  as  It  Covers  a  Strip  Sixty  Feet 
Wide 410 

Fig.  182— Avery  Gas  Tractor  Outfit  Owned  by  D.  M. 
Circle,  Kiowa,  Kansas,  Pulling  a  Double  Disc  and 
Lever  Tooth  Harrow 411 

Fig.  183 — Details  of  Easily  Constructed  Harrow  Hitch  for 

Four  Ten  Foot  Disc  Harrows 412 

Fig.    184 — Practical    Application    of    I.    H.    C.    "Mogul" 

Tractor  in   Road  Grading  Work 412 

Fig.  185— Avery  Gas  Tractor  Pulling  Western  Wagon  Loader 

and  Elevator  Grader '  .  .   413 

Fig.  183 — -Practical  Hitch  for  Pulling  Three  Road  Scrapers 

Simultaneously 415 

Fig.    187 — Special   Wagon   Adapted   to  be   Used  in   Train 

Hauled  by  Gas  Tractor 416 

Fig.  188 — Combination  Road  Roller  and  Tractor,  an 
Extremely  Useful  Machine  for  General  Contractors  or 
Municipal  Use.  A — Machine  With  Roller  for  Steering 
and  Auxiliary  Rims  on  Traction  Members.  B — 
Roller  Removed  from  Front  and  Wheels  Substituted, 
Making  Practical  Tractor  for  Road  or  Field  Work     .   417 

Fig.    189 — Harvesting  With  Avery  Gas  Tractor  in  North 

Dakota 418 

Fig.  190—1.  H.  C.  Gas  Tractor  Pulling  Three  McCormick 

Harvesters 419 

Fig.  191— The  Threshing  Outfit  Entrained  Ready  for 
Trip  to  Destination  in  Upper  View.  Outfit  at  Work 
in  Field  in  Lower  View 421 

Fig.  192— Gas    Tractor    Not    Only    Cuts    but    Stores   the 

Fodder 422 


List  of  Illustrations  xxxi 

Fig.  193 — Holt  Caterpillar  Tractor  Demonstrates  Its  Worth 

In  Swampy  Ground 424 

Fig    194 — The   Modern    Gas    Tractor    Makes    Hauling    of 

Heavy  Logs  a  Commercial  Proposition   ....    425 

Fig.  195 — An  Auitman  &  Taylor  Tractor  Operating  in  Deep 
Snow,  Shows  That  All  the  Year  Round  Service  May  be 
Obtained  from  the  Modern  Gas  Tractor        .        .        .421) 

Fig.     196 — Ingenious     Home-made     Light     Tractor     Saw 

Constructed  by  F.  J.  Jantz  of  Hilsboro,  Kansas      .        .    427 

Fig.  197 — Home-made  Gas  Tractor  Outfit  Built  by  John  H. 

Sands,  Cavalier,  North  Dakota 428 

Fig.  198 — Method  of  Installing  Auto-tractor  Under  Rear 
Axle  of  Car  and  General  Construction  of  the  Attach- 
ment Outlined 429 

Fig.  199 — Side  View  of  Automobile,  Equipped  With  Auto- 
tractor  Attachment 431 

Fig.  200 — Rear  View  of  Automobile  With  Auto-tractor 
Attachment,  Showing  Practical  Application  in  Plough- 
ing   434 

Fig.   201 — Plan   of   Easily   Constructed   Prony   Brake   for 

Making  Power  Tests 443 

Fig.  202 — A  Simple  Method  of  Determining  Grade  Per- 
centages Without  a  Gradometer        .....    447 

Fig.  203 — Road  Signs  of  American  Motor  League  That 
Give  Warnings  of  Interest  to  Tractor  Operators  or 
Motorists 450 

Fig.  204 — Belt  Driven  Centrifugal  Pump  Suitable  for 
Irrigation  Purposes  May  be  Driven  by  Direct  Connec- 
tion With  Belt  Pulley  of  Gas  Tractor  Power  Plant     .   461 


THE  MODERN  GAS  TRACTOR 

CHAPTER  I. 

THE  SCOPE,  ADVANTAGES  AND  APPLICATION  OF 
POWER  TRACTION. 

Influence  of  Mechanical  Power  on  the  Arts — Application  of 
Power  in  Agriculture — Advantages  of  Power  Traction — 
Comparison  Between  Work  of  Horse  and  Tractor — Thermal 
Efficiency  of  Horse — Tractor  Furnishes  Power  for  Various 
Farm  Machines — Economical  Aspect  of  Power  Traction — 
Analysis  of  Requirements  of  Ideal  Tractor — Practical  Prime 
Movers — Comparing  Steam  and  Gas  Power  from  a  Prac- 
tical Point  of  View — Efficiency  of  Steam  and  Gas  Power — 
Why  Gas  Tractors  Are  Most  Popular. 

Influence  of  Mechanical  Power  on  the  Arts. — The 

discovery  of  the  expansive  power  of  steam  and  the  de- 
velopment of  the  practical  steam  engine  by  Watt  was  the 
inception  of  the  era  of  supremacy  of  mechanical  power 
and  the  decline  of  animal  energy  in  the  mechanical  arts. 
The  first  steam  engine  was  devised  to  draw  water  out  of 
mines  with  greater  celerity  than  prevailed  with  animal 
power,  the  only  source  of  work  available  when  natural 
forces,  such  as  wind  or  falling  water  could  not  be  used 
and  though  crude  in  form,  it  was  not  long  before  it  had 
conclusively  demonstrated  its  superiority  as  a  prime 
mover  and  was  generally  used  to  replace  animal  power  in 
the  industrial  establishments  and  workshops  of  the  day. 
When  the  steam  engine  had  been  developed  still  fur- 
ther, other  inventors  sought  to  apply  it  to  the  wide  field 

33 


34 


The  Modern  Gas  Tractor 


of  transportation.  Early  in  the  19th  century  the  steam- 
boat contrived  by  Robert  Fulton  proved  without  ques- 
tion that  navigation  by  mechanical  power  was  possible, 
and  a  little  later,  road  vehicles  were  devised  that  ran 
without  horses.  The  opposition  of  the  ignorant  public 
prevented  further  development  and  some  countries, 
notably  England,  passed  laws  excluding  such  self-pro- 


Fig.  1.— The  Method  of  Ploughing  in  Vogue  for   Over  5,000 
Years.      Animal  Drawn  Single  Furrow  Plough. 


pelling  vehicles  from  the  highways.  Ignorance  has 
always  been  a  bar  to  progress,  and  thus  the  antipathy  of 
an  uneducated  populace  delayed  the  development  of  the 
modern  automobile  by  over  half  a  century. 

While  the  steam  engine  and  other  forms  of  prime  mov- 
ers soon  displaced  horse  and  human  power  in  the  field  of 
mechanical  engineering  and  general  manufacturing,  ani- 


The  Modern  Gas  Tractor  35 

mal  power  has  remained  for  years  supreme  in  the  oldest 
and  most  important  industry  of  mankind,  agriculture. 
In  most  countries  it  is  the  horse,  ass  or  ox  that  is  used  for 
drawing  the  ploughs  and  other  machines  utilized  for  til- 
ling the  soil.  In  India  and  parts  of  Africa  the  elephant 
is  used,  in  Asia  the  camel  furnishes  power.  Domesti- 
cated buffalo,  reindeer,  or  dogs  serve  as  motive  power 
in  other  localities  while  the  pioneer  Doukhabor  farmer 
of  Canada,  when  too  poor  to  purchase  horseflesh  har- 
nessed  ten  or  twelve  women  to  the  plough  and  thus  tilled 
the  virgin  soil  that  soon  gave  him  a  competence. 

Application  of  Power  in  Agriculture. — Agricul- 
ture is  the  basis  of  any  country's  prosperity.  It  is  the 
most  important  of  the  occupations  of  man  because  it  fur- 
nishes the  majority  of  the  foodstuffs  that  sustain  life.  A 
country  that  cannot  grow  enough  food  for  its  population 
is  always  in  grave  danger,  and  no  matter  how  large  its 
other  resources  may  be,  it  is  always  at  the  mercy  of  those 
states  that  are  able  to  feed  their  people.  Of  late  years,  a 
number  of  conditions  have  served  to  direct  public  inter- 
est to  the  farmer  and  the  important  bearing  his  work 
bears  to  the  general  welfare  of  the  people.  The  increas- 
ing cost  of  living,  the  high  prices  for  the  bare  necessities 
of  life  demands  careful  consideration  and  scientific  appli- 
cation of  principles  that  will  increase  the  farmer's  effi- 
ciency. It  is  more  important  that  the  cost  of  producing 
the  food  of  man  be  reduced  than  that  of  any  other  thing. 
It  takes  good  food  and  plenty  of  it  to  conserve  human 
and  animal  life  and  efficiency.  , 

Just  as  mechanical  power  increased  production  and 
reduced  cost  of  our  manufactured  products  to  such  an 
extent  that  the  luxuries  of  kings  of  but  a  century  ago 
are  available  to  the  poorest  workman  of  to-day,  so  its 
general  application  to  the  farmer's  work  will  increase 


36 


The  Modern  Gas  Tractor 


the  productiveness  of  his  fields.  It  will  give  him  more 
time  for  the  intelligent  direction  of  his  activities  by 
reducing  the  daily  grind  of  incessant  toil  heretofore  his 
lot;  and  increase  his  wealth  and  purchasing  power  and 
thus  benefit  the  public  at  large  in  many  ways.  The  pos- 
sibilities of  expansion  of  our  already  large  agricultural 
industry  by  application  of  mechanical  power  to  the  fields, 


Fig.  2. — The  Modern  Method  of  Soil  Tillage.  Mechanical  Power 
Furnished  by  Gas  Tractor  Pulls  Six  Ploughs  at  Once.  Some 
Tractors  Powerful  Enough  to  Make  Fourteen  Furrows  at  a 
Time. 


workshop  and  even  households  of  our  rural  population 
can  be  adequately  grasped  only  by  a  study  of  sociology 
and  economics  that  is  obviously  not  within  the  scope  of 
a  mechanical  treatise. 


The  Modern  Gas  Tractor  37 

Advantages  of  Power  Traction. — Theie  is  no  point 
about  the  farm  where  power  is  more  necessary  than  in 
the  fields,  and  it  is  said  that  more  energy  is  spent  in 
plowing  annually  than  in  the  combined  factories  of  the 
world  during  the  same  period.  The  earliest  plow  was  a 
crotched  stick  and  served  to  till  the  ground  for  the  first 
of  our  primitive  ancestors  who  conceived  the  idea  that 
breaking  the  ground  was  the  first  step  and  one  of  the 
most  important  that  had  bearing  upon  the  growth  of 
the  seed  sowed  therein.  Plowing  has  always  demanded 
more  expenditure  of  energy  and  time  than  all  other  lines 
of  farm  work  combined.  History  records  that  the 
Chinese  Emperor  Shen  Neng  who  assumed  the  sceptre 
nearly  3,000  years  before  the  beginning  of  the  Christian 
era,  "first  fashioned  timber  into  plows."  For  over  5,000 
years  ploughing  has  been  done  by  animal  power  and  the 
feet  of  the  larger  majority  of  our  farmers  are  still  in  the 
furrow,  their  arms  still  control  and  guide  the  plough. 

The  call  first  came  for  power  to  pull  the  plough,  to 
make  many  furrows  in  the  time  usually  taken  to  make 
one.  The  earth  must  be  ploughed  at  a  certain  time, 
and  under  sharply  defined  conditions.  To  violate  any 
of  the  rules,  either  of  time  or  thoroughness  of  tillage 
makes  material  difference  in  the  quality  and  quantity  o£ 
the  crops.  The  amount  of  land  tilled  depended  upon 
the  equipment  of  the  farmer  and  the  endurance  of  his 
employees  and  horses.  At  best,  the  area  ploughed  was 
generally  but  a  small  percentage  of  the  ground  available 
for  cultivation.  The  crops  were  limited  and  the  pro- 
ductive ability  of  the  farm  was  relatively  low  in  com- 
parison to  what  power  makes  possible. 

The  first  steam  ploughing  engine  is  credited  to  J.  W. 
Fawkes,  and  was  buKt  in  1858.  It  drew  eight  plows  in 
prairie  sod  at  the  rate  of  three  miles  per  hour.    The  first 


38  The  Modern  Gas  Tractor 

gasoline  tractor  was  placed  on  the  market  in  1893  but 
could  not  compare  with  the  steam  tractor  because  of 
the  crudeness  of  the  gasoline  engine  of  that  period.  It 
was  not  until  1903  that  the  gas  tractor  became  a  com- 
mercial success.  The  development  of  the  practical 
internal  combustion  tractor  was  even  more  important 
than  the  invention  of  the  mechanical  reaper  and  binder 
or  the  threshing  machine.  It  gave  the  agricultural 
industry  the  power  that  was  needed,  and  its  advent 
marks  the  greatest  jump  of  progress  in  the  history  of 
agriculture.  From  its  advent,  barely  a  decade  ago,  the 
story  has  been  one  of  steady  progress.  Difficulties  have 
been  gradually  eliminated  and  to-day  one  may  say 
that  many  of  the  tractors  sold  have  reached  a  high 
efficiency,  while  all  made  by  reputable  manufacturers 
are  practical  and  capable  of  wide  application.  It  is 
estimated  that  over  seventy-five  firms  are  offering  gas 
tractors  of  all  varieties  and  the  sales  at  the  present  time 
run  well  up  into  the  thousands  yearly.  They  have  been 
shipped  to  all  parts  of  the  civilized  world,  yet  the  indus- 
try is  but  in  its  infancy. 

Power  traction  is  superior  to  animal  energy  because 
it  will  do  more  work  in  a  given  time  at  less  expense  than 
possible  with  any  other  traction  means.  It  can  be 
adapted  to  tasks  that  cannot  be  accomplished  by  any 
other  power  and  it  is  always  ready  for  work.  When 
intelligently  managed  its  operating  cost  is  so  much  less 
than  that  of  horses  necessary  to  do  the  same  work  or 
the  amount  of  work  done  in  a  given  time  is  so  much 
greater  than  possible  with  any  other  form  of  power  of 
the  same  cost  that  its  merits  are  apparent  to  any  one 
able  to  analyze  its  performance. 

Comparing  Work  of  Horse  and  Tractor. — A  brief 
summing  up  of  the  comparative  merits  of  horse-power 


The  Modern  Gas  Tractor  39 

and  mechanical  energy  show  clearly  the  reason  why  the 
animal  is  doomed  to  give  way  to  the  gas  tractor  on 
everything  except,  perhaps,  very  small  farms,  and  even 
in  this  field  of  application,  some  of  the  lighter  tractors 
are  available  and  will  do  anything  the  animal  can  and 
much  work  that  the  horse  cannot  be  made  to  perform. 
In  the  prime  advantage  of  economy,  both  in  time  and 
money,  the  tractor  is  cheaper  by  a  wide  margin.  A 
tractor  works  in  any  kind  of  weather  without  fatigue. 
The  horse  is  affected  by  extremes  of  temperature,  either 
hot  or  cold.  The  horse  is  subject  to  all  ills  that  flesh  is 
heir  to,  if  the  animal  breaks  down,  nature  is  the  only 
possible  repairman  and  it  works  slowly. 

The  tractor  is  machinery,  any  one  of  average  intelli- 
gence can  replace  worn  or  broken  parts  with  but  slight 
delay.  The  tractor  feels  neither  heat  or  cold.  It  will 
work  equally  well  in  the  torrid  heat  of  summer  or  the 
icy  blasts  of  winter.  A  tractor  can  be  housed  cheaper 
than  the  number  of  horses  needed  to  do  the  same  work 
can,  it  requires  no  care  and  does  not  eat  when  not  in  use 
as  horses  do.  Its  days  work  is  limited  only  by  the  num- 
ber of  hours  in  the  day  and  the  endurance  of  its  operators. 
Its  working  period  is  not  measured  by  periods  of  6,  8,  or 
10  hours,  with  frequent  stops  for  rest.  The  tractor  will 
work  24  hours  per  day,  and  pull  as  strong  the  last  minute 
of  the  period  as  when  first  started. 

To  be  convinced  of  the  relative  value  of  horse  and 
mechanical  power,  one  can  compare  the  original  cost  of 
any  tractor  with  the  first  cost  of  a  sufficient  number  of 
horses  to  do  an  equal  amount  of  work.  The  comparison 
favors  the  tractor.  If  one  compares  the  maintenance 
cost  of  the  two  outfits,  the  machine  is  overwhelmingly 
superior  to  the  animal.     Compare  the  amount  of  work 


40 


The  Modern  (J as  Tractor 


accomplished  by  them  and  its  approximate  cost,  you 
will  soon  appreciate  the  value  of  the  tractor.  A  farmer 
cannot  afford  to  feed  and  house  the  number  of  horses 
necessary  to  do  the  work  a  50  or  60  horse-power  tractor 
can. 


Fig.  3. — A  Man  Easily  Carries  Fuel  and  Water  Enough  for  an 
Extended  Period  of  Operation  When  Gas  Engine  is  Used 
for   Power. 

Thermal  Efficiency  of  the  Horse. — The  horse  may 
be  considered  as  a  motor  in  the  sense  that  it  utilizes  the 
heat  units  contained  in  its  food,  which  represents  the 
fuel  that  is  burnt  in  the  cylinder  of  the  gasoline  engine 
or  under  the  steam  boiler.  The  ratio  between  the  energy 
given  out  by  the  animal  and  the  amount  of  fuel  consumed 
i  espresents  the  thermal  efficiency,  or  utilization  of  heat  re- 
lative to  work  done.     There  are  different  methods  of  com- 


The  Modern  Gas  Tractor  41 

paring  the  efficiency  of  the  horse  and  the  inanimate  engine. 

The  engineer  considers  the  ratio  of  the  heat  units 
delivered  by  the  motor  as  useful  work  to  the  total  heat 
units  in  the  fuel  supply.  The  student  of  animal  physi- 
ology first  determines  the  number  of  digestible  elements 
contained  in  a  given  food  and  considers  this  the  fuel 
value  of  the  feed.  It  is  said  that  30  per  cent,  of  the  fuel 
value  of  food  is  lost  in  the  energy  expended  by  the  ani- 
mal in  chewing  and  digesting  it.  In  addition  to  a  food 
having  a  fuel  value  it  also  has  a  maintenance  value.  The 
amount  of  external  work  that  can  be  obtained  when  the 
animal  is  given  a  certain  definite  amount  of  food  is 
termed  the  "production  value."  Even  when  the  horse 
is  working  a  certain  proportion  of  energy  is  being  con- 
sumed in  moving  its  body  and  as  it  is  able  to  deliver 
work  only  when  in  motion  the  thermal  efficiency  of  the 
horse  is  very  low,  being  given  as  not  more  than  6  to  10 
per  cent.  This  is  exceeded  by  most  internal  combustion 
tractors.  Experts  of  the  U.  S.  Department  of  Agricul- 
ture have  obtained  an  efficiency  of  20  per  cent,  under 
laboratory  conditions.  While  this  may  be  true  of  scien- 
tifically fed  animals  under  careful  supervision,  the  horses 
that  work  under  actual  farm  conditions  have  a  much 
lower  efficiency. 

Many  experiments  have  been  made  to  determine  the 
actual  power  of  a  horse.  James  Watt,  the  inventor  of 
the  steam  engine,  placed  the  working  power  of  a  1,500- 
pound  animal  as  the  ability  to  lift  33,000  pounds  to  a 
height  of  one  foot  each  minute  or  >  550  pounds  to  the 
same  height  each  second.  This  originated  the  term 
"horse-power"  which  has  been  used  in  the  mechanical 
world  ever  since  these  classical  experiments  were  made 
as  a  unit  for  the  measurement  of  power  delivered  from, 
or  consumed  by  mechanical  devices. 


42  The  Modern  Gas  Tractor 

Recent  experiments  seem  to  indicate  that  the  work 
performed  by  the  average  animal  approximates  22,000 
foot-pounds  per  minute,  or  two-thirds  of  a  horse-power. 
Other  investigators  declare  that  the  average  horse  will 
deliver  three-quarters  of  an  actual  horse-power.  The 
working  ability  of  a  horse  is  measured  by  its  pulling 
power  which  is  called  "draft"  and  it  is  on  this  basis  that 
traction  engines  are  compared  to  horse  flesh.  The  pull- 
ing power  of  the  animal  is  given  at  one-tenth  of  its  weight 
when  working  continuously  ten  hours  each  day  pulling 
some  object  at  the  rate  of  23^  miles  per  hour.  Under 
these  conditions  a  1,200-pound  horse  will  develop  but 
eight-tenths  of  a  horse-power  and  a  1,500-pound  ani- 
mal one  horse-power. 

For  short  periods  the  horse  may  exert  a  maximum 
draft  of  about  one-half  its  weight  but  obviously  this 
work  cannot  be  done  continuously  and  the  amount  of 
energy  can  be  exerted  for  but  a  short  time  without 
injury.  The  pulling  power  of  the  average  plough  horse 
is  given  as  150  pounds.  One  horse-power  is  equal  to  a 
draft  of  187.5  pounds  at  the  rate  of  two  miles  per  hour. 
It  is  evident  that  no  matter  whether  one  considers  the 
horse  from  a  practical  or  scientific  point  of  view  that 
mechanical  power  shows  a  marked  advantage  over  ani- 
mal energy. 

Tractor  Furnishes  Power  for  Various  Farm  Ma= 
chines. — We  have  seen  that  the  horse  can  do  its  best 
work  only  when  pulling  a  load.  If  used  for  power 
through  the  medium  of  a  tread-mill,  for  operating  vari- 
ous forms  of  machines,  the  efficiency  is  still  lower  and 
the  ratio  between  useful  work  obtained  and  amount  of 
food  consumed  is  such  that  it  is  not  economical  to  utilize 
the  animal  in  this  way.  The  usefulness  of  a  tractor  is 
more  varied  than  that  of  any  other  farm  machine.     It 


The  Moderx  Gas  Tractor 


43 


is  not  only  the  most  economical  power  for  ploughing 
hut  it  operates  with  equal  economy  all  the  machines 
and  appliances  necessary  for  raising  and  harvesting 
crops.  These  include  disk  harrows,  seeders,  drills, 
packers,  binders,  etc. 

It  can  be  used  for  hauling  grain  to  the  elevator,  pulling 
stumps  and  hauling  all  kinds  of  lumber  and  supplies  to 


WATER    YYACOH 


KhmttJtf'    '      J-'—       111*--  )        7* 


Fig.  4. — The  Caravan  Needed  to  Keep  a  Steam  Traction  Engine 
Supplied  With  Fuel  and  Water  is  a  Large  Item  in  Operat- 
ing Costs. 

the  farm.  Most  tractors  can  be  used  for  stationary 
power  and  a  belt  may  be  run  from  the  pulley  provided 
for  the  purpose  to  operate  threshers,  shellers,  shredders, 
pumps,  sawing  outfits  and  any  other  form  of  machine 
needing  power.  It  has  sufficient  power  to  run  a  large 
number  of  machines  at  a  time  if  the  main  drive  is  con- 
nected to  a  line  shaft  which  will  turn  a  number  of  ma- 
chines in  unison. 


II  The  Modern   <!as  Tractor 

The  gasoline  traction  engine  is  assuming  increased 
importance  in  contracting  and  road  construction  work. 
Operating  expenses  of  a  tractor  are  materially  less  than 
when  animals  are  employed  because  the  amount  of  help 
needed  is  reduced  to  a  minimum.  One  man  easily  does 
the  work  of  three  or  four.  The  fact  that  it  requires  no 
attention  and  consumes  no  fuel  when  not  in  use  is  an 
advantage  not  possessed  by  animal  power.  Horses  must 
be  wintered  and  for  a  number  of  months  they  are  con- 
suming food  and  giving  no  useful  work  in  return. 

The  amount  of  land  that  is  now  given  over  to  culti- 
vation of  food  for  horses  and  other  draft  animals  could 
be  just  as  well  used  in  raising  the  food  elements  needed 
by  the  human  race.  The  tractor  consumes  nothing  that 
has  any  definite  food  value  or  that  can  be  utilized  by  the 
people  to  better  advantage  than  it  is  as  fuel  in  producing 
power. 

The  tractor  knows  no  seasons  and  on  any  farm,  work 
can  be  found  for  it  at  all  times.  It  will  pull  the  ploughs 
and  drills  in  the  spring;  in  the  summer  it  can  be  used 
for  making  roads  and  hauling  supplies;  in  the  fall  it  can 
operate  a  binder  or  thresher;  in  the  winter  it  may  be 
used  as  power  for  a  sawing  outfit,  or  for  running  a  husker, 
shredder,  or  sheller.  Between  seasons  it  will  do  heavy 
hauling,  pump  water,  cut  ensilage,  operate  grinding 
mills,  haul  manure,  bale  hay  and  dig  ditches.  The  large 
range  of  use  to  which  the  average  tractor  can  be  adapted 
and  the  relatively  slight  cost  for  its  maintenance  cannot 
fail  to  impress  the  economical  owners  of  farms  who  are 
conducting  them  on  a  business  basis  and  to  whom  great 
efficiency  and  lower  cost  of  production  means  vastly 
increased  profits. 

Economical    Aspect    of    Power    Traction. — The 


The  Modern  Gas  Tractor  45 

farmer  who  is  just  beginning  to  realize  that  power  trac- 
tion offers  many  advantages  is  desirous  of  ascertaining 
just  what  the  average  tractor  will  accomplish  for  him 
and  at  what  cost.  He  is  not  satisfied  to  read  general 
claims  of  desirability,  adaptability  or  economy.  He 
wishes  definite  figures.  He  desires  to  know  how  much 
1  tetter  and  how  much  cheaper  the  farm  tractor  can  do 
his  work  than  the  same  amount  can  be  accomplished 
with  horses  and  farm  hands. 

One  of  the  great  difficulties  of  farming  on  a  large  scale 
by  old  methods  exists  in  the  fact  that  certain  work  must 
be  accomplished  at  a  definite  time.  The  ploughing,  the 
seeding,  harvesting  and  threshing  must  all  be  done  dur- 
ing definite  periods.  This  work  must  be  in  progress 
while  climatic  and  weather  conditions  are  right.  It  is 
at  this  time  that  the  capacity  and  endurance  of  mechani- 
cal power  is  emphasized  and  the  wonderful  superiority 
of  the  tractor  over  horses  and  farm  hands  made  evident. 

The  value  of  early  fall  ploughing  is  generally  accepted, 
as  under  this  treatment  the  weeds  are  turned  under  the 
sod  while  still  green  and  the  decaying  vegetable  matter 
forms  an  invaluable  fertilizer.  The  weeds  all  bear  seed 
which  would  sprout  in  the  spring  under  ordinary  cir- 
cumstances. Ploughing  brings  these  near  the  surface 
and  as  they  commence  their  growth  before  winter  comes 
the  frosts  soon  put  an  end  to  this  objectionable  vegetable 
growth.  The  result  is  a  field  free  from  weeds  for  the  next 
grain  crop. 

The  agriculturist  who  uses  a  tractor  for  threshing  is 
able  to  do  it  as  soon  as  the  grain  is  ready.  If  this  is  inter- 
rupted by  rain  the  tractor  can  be  utilized  for  ploughing 
and  under  these  circumstances  many  farmers  have  fin- 
ished their  fall  ploughing  almost  as  soon  as  they  have 
completed  their  threshing  operation. 


46 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  47 

Another  work  that  requires  to  be  done  promptly  is 
harvesting.  This  is  usually  done  in  very  hot  weather, 
and  both  horses  and  men  suffer  from  working  in  the 
excessive  heat.  If  one  has  a  large  area  under  cultivation 
and  no  men  are  available  for  the  harvesting,  it  will  not 
take  much  inclement  weather  to  destroy  grain  of  a  value 
greater  than  that  of  a  tractor  that  might  have  harvested 
the  entire  crop  at  the  proper  time. 

A  gas  tractor  not  only  effects  a  striking  economy 
but  it  multiplies  the  efficiency  of  every  piece  of  machin- 
ery or  implement  on  the  farm  not  operated  by  human 
power.  No  agriculturist,  worthy  of  the  name,  will  ques- 
tion that  the  self-binder  is  a  great  invention,  as  are  also 
the  drill,  mowing  machine,  the  disk  or  toothed  harrow 
and  the  gang-plough.  The  development  of  modern 
farming  is  due  to  all  of  these  implements,  yet  each  is 
limited  in  usefulness  by  the  cost  of  the  power  required  to 
operate  it.  Any  of  these  implements  attached  to  the 
powerful,  quickly  moving  and  economically  operated 
gas  tractor  has  a  greatly  increased  value  over  that  pos- 
sessed when  only  the  more  expensive  and  less  efficient 
horse  traction  is  available.  The  following  figures  are 
given  by  a  prominent  tractor  manufacturer,  the  Gas 
Traction  Company,  as  the  average  cost  under  ordinary 
conditions  for  the  various  tasks  enumerated. 

FLOUGHING 

Thirty  acres  considered  the  average  day's  work. 

One  engineer  and  board,  $75.00  monthly $3.00 

Forty-five  gallons  gasoline  at  16  cents 7.20 

Lubricating  oil  and  grease 1.50 

$11.70 
Cost  per  acre 39 


48 


The  Modern  Gas  Tractor 


BREAKING. 

Twenty-five  acres  considered  the  average  day's  work. 

One  engineer  and  board,  $75.00  monthly $3.00 

Fifty  gallons  gasoline  at  16  cents 8.00 

Lubricating  oil  and  grease 1.50 

112.50 
Cost  per  acre 50 

The  point  is  emphasized  that  the  above  tables  apply 
to  average  conditions  and  one  must  draw  his  own  con- 
clusions as  to  what  can  be  accomplished  in  his  specific 


COOLER     POWER  PLANT  j  _^S 


FRONT  !&;',;:;!;! 
AXLE  Ki,A*- 


DRIVING  WHEEL 


Fig.  6. — Typical  Large  Capacity  Gas  Tractor  of  Latest  Approved 
Design,  with  Important  Parts  Clearly  Shown. 

case.  In  exceptionally  heavy  gumbo  the  average  cost 
will  be  greater  but  in  lighter  sandy  loam  it  will  be  easy 
to  reduce  the  cost.  In  these  tables  depreciation  and 
interest  on  the  investment  are  not  included  because  this 
is  an  uncertain  quantity. 

The  big  advantage  of  the  gas  tractor  is  realized  in 
threshing.  The  average  gas  tractor  of  25  to  30  horse- 
power will  drive  any  make  of  separator  and  one  engi- 


The  Modern  Gas  Tractor  49 

neer  operates  both  power  plant  and  threshing  machine 
because  he  has  no  duties  to  occupy  him  after  the  tractor 
arrives  at  the  destination.  There  is  no  steam  pressure 
to  keep  up,  no  fuel  to  handle,  no  water  gage  to  watch 
and  no  danger  of  fire  around  the  engine  due  to  sparks. 
The  engine  will  run  smoothly  for  hours  without  atten- 
tion because  it  is  automatically  lubricated  and  the  fuel 
supply  is  continuous  as  long  as  any  remains  in  the  tank. 
The  Gas  Traction  Company,  in  speaking  of  the  use  of 
the  Big  Four  "30"  in  threshing,  state,  that  this  machine 
will  drive  a  36-inch  separator  of  any  standard  make. 
The  engineer  is  to  run  the  separator,  as  well  as  the 
engine,  two  good  pitchers  being  employed  to  feed  the 
machine  and  four  dump  racks,  with  a  man  and  team  of 
horses  for  each  to  haul  the  bundles  to  the  pitchers  at  the 
separator.  The  gas  tractor,  with  the  separator  attached 
can  quickly  change  its  stand  and  keep  near  to  the  grain 
to  be  threshed.  This  makes  a  short  haul  for  the  teams 
bringing  the  bundles  and  requires  fewer  men  and  teams 
than  a  steam  rig,  threshing  the  same  amount  of  grain. 
It  is  claimed  that  this  small  crew  of  seven  men  will 
easily  thresh  from  1,000  to  1,800  bushels  per  day,  accord- 
ing to  the  character  and  weight  of  the  grain.  This  may 
be  done  at  a  cost  of  labor,  teams  and  fuel,  as  follows: 

THRESHING. 

One  engineer's  wages  and  board $5.00 

Two  pitchers'  wages  and  board 6.50 

Four  teams  and  men  at  $5.00  each 20.00 

Thirty-five  gallons  gasoline  at  16  cents 5.60 

Lubricating  oil 1 .00 

$38.10 
Average  amount  threshed  of  wheat,  running  15  bushels 
per  acre,  1,400  bushels.     Cost  of  threshing  a  little  less 
than  2%  cents  per  bushel. 


50  The  Modern  Gas  Tractor 

If  the  gas  tractor  is  suitable  for  the  heavier  work  of 
ploughing  and  breaking,  it  is  obvious  that  its  capacity 
for  the  lighter  form  of  traction  work  must  be  very  great. 
The  high  wide  wheels  and  the  relatively  light  weight  of 
the  average  tractor  enable  them  to  travel  over  the  ground 
without  sinking  in  or  packing  the  soil.  A  tractor  will 
draw  any  load  where  horses  will  draw  it.  Consequently 
the  farmer  need  not  keep  horses  eleven  months  to  do  one 
month's  work.  A  30  horse-power  tractor,  for  example, 
will  draw  four  10-foot  drills,  six  8-foot  disks,  and  all  the 
harrows  that  can  be  conveniently  hitched  on.  With 
four  10-foot  drills  and  two  20-foot  drags  behind,  two 
men  can  drill  and  drag  from  100  to  150  acres  per  day  at  a 
cost  under  25  cents  per  acre. 

The  great  inventor,  Thomas  A.  Edison,  is  credited 
with  the  following  quotation:  "An  invention  that  will 
enable  the  farmer  to  harvest  his  crop  cheaper,  better  and 
faster  than  heretofore,  is  worth  $100,000,000."  It  is 
not  difficult  to  arrange  hitches  to  enable  tractors  to  pull 
drills,  drags,  ploughs,  or  any  other  implement  where  the 
engine  has  a  straight  pull  and  a  clear  field.  It  was  a 
more  difficult  matter,  however,  to  perfect  a  hitch  by 
which  several  binders  could  be  drawn  after  the  engine, 
the  tractor  running  at  the  edge  of  the  grain,  and  the 
binders,  each  cutting  its  full  swath  off  at  one  side. 
There  could  not  be  any  side  draft,  no  running  over  uncut 
grain  or  bundles,  and  the  natural  side  draft  of  the  bind- 
ers themselves  must  be  overcome.  At  the  present  time 
various  hitches  have  been  perfected,  so  that  a  large 
number  of  binders  of  any  size  or  make  may  be  operated 
in  connection  with  the  average  tractor. 

The  following  summary  shows  in  a  broad  general  way 
a  statement  of  what  a  representative  tractor  could  do  in 
volume  of  work  and  at  what  cost: 


The  Modern  Gas  Tractor  51 

volume  of  work. 

Breaking,  per  day 20  to  40  acres 

Stubble  ploughing,  per  day 25  to  50  acres 

Drilling  and  harrowing,  per  day.  .  .     100  to  150  acres 

Double-disking,  per  day 60  to  75  acres 

Harvesting,  per  day 60  to  100  acres 

Threshing  wheat,  per  day 1,400  to  2,500  bushels 

COST    OF    WORK. 

Breaking $0.50  to  $0.75  per  acre 

Stubble  ploughing 40  to      .50  per  acre 

Drilling  and  harrowing 20  to      .25  per  acre 

Double  disking 10  to      .20  per  acre 

Harvesting  (exclusive  of  twine) :  .  .20  to  .30  per  acre 
Threshing 03  per  bushel 

The  gasoline  used  is  given  as  two  gallons  per  acre 
while  breaking  prairie  sod.  Stubble  ploughing  consumes 
about  \}A  gallons  per  acre.  The  engine  will  use  but  35  gal- 
lons when  threshing  an  entire  day.  In  general  the  oper- 
ating expense  of  a  tractor,  providing  that  work  enough 
is  at  hand  to  keep  it  working  to  capacity,  will  be  about 
one-third  the  operating  expense  of  the  number  of  horses 
necessary  to  do  this  same  work.  It  will  reduce  the  num- 
ber of  hired  help  needed  by  two-thirds,  and  if  there  are 
young  people  on  the  farm  its  value  cannot  be  estimated 
easily,  because  it  accomplishes  the  important  result  of 
converting  an  old-time  humdrum  and  laborious  occupa- 
tion into  an  interesting  up-to-date  business. 

Analysis  of  Requirements  of  Ideal  Tractor. — 
The  requirements  of  the  ideal  tractor  can  be  summed  up 
as  follows.  First,  it  should  have  universal  adaptability. 
in  order  to  be  able  to  accomplish  all  kinds  of  belt  or  draw- 
bar work,  as  it  is  only  by  having  a  machine  that  is  ap- 
plicable to  a  large  variety  of  tasks  that  one  can  justify 
the  investment  needed  to  purchase  a  practical  machine. 


52 


The  Modern  Gas  Tractor 


The  Modern  Has  Tractok 


53 


It  should  be  capable  of  operating  every  machine  on  the 
farm  that  requires  power. 

Second,  it  should  have  correct  weight  for  the  work  it 
is  to  do  and  the  proper  arrangement  of  components.  A 
logical  distribution  of  weight  is  necessary  to  insure  proper 
traction.  If  the  machine  is  too  heavy  it  will  pack  the 
soil  and  much  power  will  be  consumed  in  moving  the 
huge  mass  over  the  ground.     The  factor  of  weight  is 


Fig.  8. — The  Wolverine  Eighteen  Horse-power  General  Purpose 
Gas  Tractor  Utilizes  Two  Cylinder  Power  Plant. 

especially  noticeable  when  climbing  grades.  If  the 
tractor  is  too  light,  it  will  not  have  adequate  adhesion 
with  the  ground  and  much  power  will  be  lost  in  slipping 
between  the  driving  wheels  and  the  ground.  The  weight 
should  be  distributed  so  the  greater  part  of  it  will  come 
over  the  rear  wheels,  as  in  most  constructions  these  are 
called  upon  to  do  the  driving. 

Third,  there  should  be  a  large  contact  area  between 
the  traction  members  and  the  ground  in  order  to  avoid 


54  The  Modern  Gas  Tractor 

loss  of  power,  packing  of  soil  and  slipping.  It  should  be 
provided  with  change  speed  gearing  that  will  provide  at 
least  two  forward  speeds  and  a  reverse  motion.  The 
drive  from  the  power  plant  to  the  rear  wheels  should  be 
positive  and  designed  so  that  there  will  be  minimum  loss 
of  energy  through  friction  in  gearing. 

Fourth,  it  should  be  of  consistent  design  for  the  work 
it  is  to  do,  built  of  the  best  materials  that  can  be  obtained 
within  reasonable  limits  and  incorporate  in  the  con- 
struction strength  without  excessive  weight.  The  entire 
mechanism,  including  the  power  plant  should  be  simple 
because  lack  of  complication  is  practical  insurance 
against  mechanical  trouble. 

Fifth,  it  should  be  easy  to  start  and  the  control  ele- 
ments should  be  designed  so  the  tractor  can  be  directed 
without  undue  expenditure  of  energy.  The  simpler  the 
control  members,  the  easier  the  average  farm-hand  will 
find  it  to  handle  the  machine.  The  construction  should 
be  such  that  an  automatic  steering  attachment  can  be 
used  in  certain  classes  of  work,  such  as  ploughing,  so  the 
engineer  may  devote  part  of  his  time  to  manipulating 
the  plough  shares. 

Sixth,  it  is  desirable  that  the  engine  be  capable  of 
operating  on  any  liquid  fuel,  especially  the  cheaper  and 
more  plentiful  distillates  of  petroleum. 

There  are  a  number  of  tractors  offered  at  the  present 
day  that  meet  all  of  the  above  requirements.  The  con- 
struction is  good  both  from  an  engineering  and  practical 
point  of  view.  The  machines  are  economical  to  main- 
tain and  operate  and  in  many  cases,  especially  in  power 
plant  and  driving  mechanism  design,  useful  lessons  have 
been  drawn  from  current  automobile  practice.  It  is  safe 
to  say  that  the  tractors  which  more  nearly  incorporate 
the  good  features  and  ideal  requirements  are  those  which 


The  Modern  Gas  Tractor  55 

follow  in  a  modified  form,  some  of  the  rules  of  practice 
established  by  automobile  designers.  In  essential  ele- 
ments the  automobile  and  tractor  are  similar.  It  is 
merely  in  detail  arrangement  of  parts  that  they  vary. 

Practical  Prime  Movers. — Three  forms  of  prime 
movers  are  available  for  mechanical  traction.  The  elec- 
tric current,,  which  has  been  used  so  successfully  in  mov- 
ing the  heavy  street  cars  and  trucks  of  our  cities  is  not 
available  for  farm-traction  engines  because  most  of 
these  are  operated  at  a  distance  from  sources  of  electric 
current.  The  steam  engine  was  formerly  very  popular, 
in  fact,  the  earliest,  really  successful  traction  engines 
were  propelled  by  steam  power.  At  the  present  time, 
however,  this  prime  mover  has  been  succeeded  by  the 
more  efficient  and  easily  understood  internal  combus- 
tion engine. 

Steam  and  Gas  Power  Compared. — One  of  the 
great  disadvantages  of  steam  power  is  that  it  requires 
skilled  supervision.  In  some  States,  the  laws  require 
that  the  operator  of  a  steam-traction  engine  shall  be  a 
licensed  engineer.  The  supervision  of  the  machine  must 
obtain  at  all  times  that  it  is  in  service  and  the  engineer 
is  too  much  occupied  in  the  various  duties  incidental  to 
keeping  up  steam  and  directing  the  conveyance  to  give 
his  time  to  any  other  work.  The  average  gas  tractor 
does  not  require  skilled  supervision.  Any  person,  who 
can  pass  the  relatively  simple  examinations  required  for 
automobile-driving  licenses  is  permitted  to  operate  a 
tractor,  providing  that  his  physical  capacity  is  equal  to 
the  task  of  starting  the  engine  and  handling  the  tractor 
under  average  operating  conditions. 

Besides  this  important  point,  the  operating  principles 
of  the  gas  engine  are  much  better  understood  at  the 
present  time  because  of  the  wide  vogue  of  gasoline  power 


56  The  Modern  Gas  Tractor 

plants  for  various  farm  uses  and  automobiles.  In  every 
community  of  any  importance  one  can  find  a  number  of 
mechanics  skilled  in  the  operation  and  repair  of  gas 
engines.  This  condition  did  not  obtain  four  or  five  years 
ago,  as  the  gas  engine  was  then  considerable  of  a  mystery 
to  our  agricultural  population.  At  the  present  time, 
however,  many  converts  to  gas  power  have  been  made 
by  the  gas-engine  manufacturer  and  thousands  of  engines 
have  been  sold.  There  are  a  number  of  other  advan- 
tages of  gas  power  that  should  be  considered  before  the 
writer  explains  why  the  gas  engine  is  the  most  popular 
prime  mover. 

Efficiency  of  Steam  and  Gas  Power. — The  thermal 
efficiency  of  the  steam  engine  is  considerably  lower  than 
that  of  the  gasoline  motor.  In  the  former,  the  heat 
units  contained  in  /the  fuel  are  made  to  do  work  by  a 
rather  roundabout  process  of  burning  the  fuel  under  a 
boiler  to  make  steam  and  then  utilizing  the  expansive 
force  of  steam  in  the  cylinders  of  the  engine  to  produce 
power.  There  is  a  big  loss  in  heat  units  in  converting 
water  to  steam  vapor  and  there  is  a  further  loss  of  heat 
when  the  steam  is  led  from  the  boiler  to  the  engine.  In  a 
gas  tractor  the  fuel  is  burned  directly  in  the  cylinders 
and  less  heat  units  are  wasted  than  in  the  steam  power 
plants. 

The  steam  engine  has  one  important  advantage  and 
that  is  that  it  can  be  operated  at  an  overload  for  some 
time.  For  example,  an  engine  with  a  nominal  rating  of 
50  horse-power  may  be  made  to  develop  60  or  70  horse- 
power by  increasing  the  steam  pressure  from  the  boiler. 
A  gas  engine  does  not  have  the  surplus  energy  to  draw 
from  and  will  not  run  under  the  overload  conditions  a 
steam  tractor  will. 

The  thermal  efficiency  of  the  average  steam-power 


The  Modern  Gas  Tractor  57 

plant  ranges  from  18  to  20  per  cent,  that  is  to  say,  only 
this  amount  of  the  heat  units  contained  in  the  fuel  burnt 
under  the  boiler  is  turned  into  useful  work  by  the  steam 
engine.  The  thermal  efficiency  of  the  gas  engine,  at  the 
other  hand,  is  often  as  high  as  30  per  cent.  When  com- 
pared on  a  basis  of  drawbar  pull,  the  relative  efficiencies 
of  steam  and  gas  tractors  do  not  vary  widely.  In  tests, 
as  in  ploughing,  steam  tractors  have  shown  an  average 
drawbar  pull  of  26  per  cent,  of  their  total  weight  and  36 
per  cent,  of  the  weight  on  the  driving  members.  Gas 
tractors  as  a  rule  will  exert  an  average  drawbar  pull  of 
25  per  cent,  of  their  total  weight  or  35  per  cent,  of  the 
weight  on  the  drivers. 

The  average  traction  rating  of  gas  tractors  are  about 
one-half  of  the  brake  horse-power  rating.  In  tests  with 
steam  tractors  over  a  firm  ploughing  course  they  were 
able  to  show  56.6  per  cent  as  much  power  at  the  drawbar 
as  at  the  belt  in  economy  tests.  Over  a  hauling  course, 
which  presented  many  different  conditions  of  road  sur- 
face from  the  very  best  to  the  poorest,  the  average  draw- 
bar horse-power  was  reduced  to  29.3  per  cent,  of  the 
power  given  by  the  engine.  In  ploughing,  some  gas 
tractors  have  shown  a  drawbar  pull  as  high  as  70  per 
cent,  of  the  engine  power,  while  in  hauling,  50. S  per  cent, 
of  the  engine  power  has  been  exerted  at  the  drawbar. 

Why  Gas  Tractors  Are  Most  Popular. — When  one 
considers  the  many  advantages,  ease  of  operation  and 
economical  maintenance  of  the  gas  tractor  it  is  not  diffi- 
cult to  understand  why  this  form  has  attained  so  great 
popularity.  The  mechanism  is  relatively  simple  and  can 
be  started  at  any  time  without  exasperating  delays.  Its 
radius  of  action  is  greater  than  that  of  a  steam  tractor 
because  it  is  more  independent  as  regards  a  base  of  sup- 
plies.   A  man  can  easily  carry  the  amount  of  water  con- 


58 


The  Modern  Gas  Tractor 


sumed  by  the  cooling  system  of  the  average  gas  engine 
in  an  ordinary  pail,  while  five  gallons  of  fuel  will  operate 
it  for  some  time.  The  steam  tractor  must  have  two  tend- 
ers. These  comprise  a  tank  wagon  for  water  and  another 
conveyance  for  wood  or  coal.  Even  if  liquid  fuel  is 
burned  under  the  boiler,  the  water  tank  will  be  neces- 
sary and  twice  as  much  liquid  fuel  will  be  needed  than 
with  a  gas  engine  of  the  same  power. 


Fig.  9. — The  1.   H.   C.   Twenty   Horse-power  Tractor  Utilizes 
Single  Cylinder  Engine  for  Power. 

Considerable  time  is  needed  to  steam  up  and  great 
care  is  necessary  if  the  steam  tractor  is  to  be  operated  in 
cold  weather.  It  is  not  profitable  or  desirable  to  use  the 
anti-freezing  solutions  in  the  boiler  that  can  be  so  con- 
veniently carried  in  the  cooling  system  of  the  gas  tractor. 


The  Modern  (Ias  Tractor  59 

The  larger  and  heavier  steam  tractors  need  two  men  to 
operate  them  just  as  a  steam  locomotive  does.  The  engi- 
neer is  occupied  in  driving  and  controlling  the  machine 
and  a  fireman  is  needed  to  keep  fuel  under  the  boiler. 
The  heaviest  gas  tractor  can  be  controlled  by  one  man. 

A  steam  tractor  must  be  relatively  heavier  than 
a  gas-operated  machine  of  the  same  power.  While  this 
may  be  considered  an  advantage  from  some  points  of 
view,  it  is  a  decided  disadvantage  in  others.  It  is 
reasonable  to  assume  that  it  takes  more  power  to 
move  a  heavy  machine  than  a  light  one.  The  more 
massive  construction  will  pack  the  ground  more  than 
that  having  less  weight  because  there  is  a  certain  limit 
to  the  size  of  the  driving  wheels  beyond  which  it  is  not 
desirable  to  go.  When  a  heavy  machine  becomes  mired 
it  is  more  difficult  to  pull  it  out  of  the  hole  by  other 
forms  of  power,  or  by  its  own  energy. 

Gas  tractors  range  in  size  from  12  to  110-brake  horse- 
power, while  steam  ploughing  tractors  are  not  economi- 
cal in  sizes  much  less  than  25  horse-power.  Ordinary 
steam-traction  engines,  when  ready  for  work,  range  in 
weight  from  10  to  25  tons.  The  gas  tractor  is  also  made 
in  many  special  designs  that  are  not  practical  with  the 
steam-propelled  types,  such  as  orchard  tractors  and  com- 
bined self-contained  ploughing  and  traction  engines. 
When  one  considers  the  wide  range  of  different  gas  trac- 
tors available,  their  generally  lower  cost  and  lighter 
weight  than  the  steamers,  the  fact  that  a  specially 
licensed  engineer  is  not  necessary  and  their  wide  adapta- 
bility, one  can  easily  understand  why  they  have  dis- 
placed the  steam-propelled  machine  in  practically  all 
lines  of  work. 


GO 


The  Modern  Gas  Tractor 


Ph 


- 

o 

S-, 

, ; 

o 

OJ 
XB 

— 

£ 

+^ 

bfl 

£ 

C 

- 

*-l 

0) 

o 

OJ 

-u 

^ 

f 

m 

Eh 

O 

GO 

£ 

o 

03 

bfl 

_: 

XII 

xr> 

7. 

- 

— 

M 

= 

ctf 

0> 

— 

H 

b9 

1 

Ph 

o 

^ 

o 

— 

CHAPTER  II. 

REVIEW  OF  CONDITIONS  ON  WHICH  TRACTOR  DESIGN 
IS  BASED. 

Elements  of  Tractor  Design  Outlined — Selection  of  Power 
Plant — Power  Needed  for  Hauling — Energy  Absorbed  by 
Ploughs — Power  Delivery  Under  Belt — Why  Proper  Dis- 
tribution of  WTeight  is  Essential— Influence  of  Weight  on 
Traction — Influence  of  Road  or  Field  Surface  on  Traction — 
Effect  of  Grades  on  Traction — Types  of  Tractors — Trac- 
tion Engines  for  Small  or  Medium  Sized  Farms — Large 
Capacity  Tractors — Parts  of  Typical  Tractors  Outlined — 
Some  Distinctive  Designs. 

Elements  of  Tractor  Design  Outlined. — The  main 
part  of  the  gas  tractor  is  the  power  plant.  Next  in  im- 
portance comes  the  traction  mechanism.  For  the  most 
part  the  gas  engines  used  in  tractor  work  contain  the 
same  essential  components  as  stationary  gas  engines 
do.  Most  of  the  earlier  tractors  used  the  common  form 
of  horizontal  cylinder  stationary  engine  as  a  power  plant 
in  the  one  and  two-cylinder  forms.  Many  of  the  present 
day  successful  machines  utilize  engines  that  are  sold  by 
the  same  manufacturers  for  stationary  work.  Some  of 
the  latest  tractors  depart  from  the  old  method  of  con- 
struction and  the  power  plants  are  based  more  on  the 
lines  of  automobile  motors  than  of  the  stationary  engines. 
The  supporting  frame,  driving  wheels,  differential  and 
power  transmission  gearing  are  not  radically  different 
from  the  same  parts  of  a  steam  tractor. 

61 


62  The  Modern  Gas  Tractor 

The  engines  of  single-cylinder  tractors  usually  run  at 
three  hundred  to  four  hundred  revolutions  per  minute. 
At  higher  speeds  than  these,  the  vibration  becomes 
excessive  and  all  parts  of  the  mechanism  are  severely 
stressed.  Two  and  three-cylinder  engines,  which  have 
a  better  running  balance,  are  usually  run  at  somewhat 
higher  speeds,  and  the  four-cylinder  type,  which  is  prac- 
tically in  perfect  balance,  both  in  that  of  the  mechanical 
parts  and  torque,  due  to  rapid  sequence  of  explosions, 
are  run  at  higher  speeds.  Some  of  these  attain  seven 
and  eight  hundred  revolutions  per  minute.  Gas  tractors 
may  be  roughly  divided  into  low,  medium,  and  high- 
speed types,  depending  on  the  type  of  power  plant  em- 
ployed. 

The  group  usually  considered  as  the  power  plant  con- 
sists of  other  elements  besides  the  engine.  Some  form 
of  vaporizer  must  be  provided  to  change  the  liquid  fuel 
to  a  gas  that  can  be  exploded  in  the  cylinder.  It  is  im- 
perative that  some  means  of  igniting  the  compressed 
charge  of  gas  be  included.  The  power  plant  must  be 
automatically  lubricated,  this  calling  for  various  devices 
for  supplying  a  regular  quantity  of  lubricant.  To  keep 
the  engine  from  overheating  some  method  of  cooling 
the  cylinder  is  always  included  in  the  power-plant  outfit. 

It  will  be  seen  that  the  power-plant  group  consists  of, 
first,  a  gasoline  or  kerosene  engine;  second,  a  method 
of  supplying  and  vaporizing  liquid  fuel,  these  members 
usually  forming  part  of  the  carburetion  system;  third, 
some  means  of  igniting  the  gas,  usually  composed  of  a 
number  of  electrical  devices  to  form  a  complete  ignition 
system;  fourth,  a  water  tank  or  radiator,  or  an  oil-cool- 
ing tank,  a  circulating  pump  for  keeping  the  liquid  in 
motion  around  the  cylinders  and  forcing  it  to  the  cooler 
where  the  heat  absorbed  is  dissipated  to  the  air.     These 


The  Modern  Gas  Tractor 


63 


various  devices  form  a  cooling  system.  Fifth,  the  lubri- 
cation system  which  comprises  positive  mechanical 
means  for  supplying  lubricant.  All  of  these  are  of  suffi- 
cient import  to  merit  a  detailed  consideration,  and  will 
be  discussed  fully  in  proper  sequence. 

The  transmission  system  comprises  a  clutch,  which  is 
used  to  connect  the  engine  power  to  the  wheels  and  to 
release  the  engine  when  desired;  a  change  speed  and 


Fig.  10a. — Side  View  of  Phoenix  Tractor,  A  Compact  Design. 

reversing  gearing,  which  is  necessary  because  the  gas 
engine  as  ordinarily  used  is  not  reversible  and  not  as 
flexible  as  the  steam  engine;  and  positive  power  trans- 
mission means,  usually  chains  or  gears,  to  transmit  the 
engine  power  from  the  change-speed  gearing  to  the  trac- 
tion members. 

A  frame  of  substantial  construction  is  needed  to  sup- 


64 


The  Modern  Gas  Tractor 


port  the  parts  and  this  in  turn  must  be  carried  on  rolling 
members.  Some  forms  of  tractors  utilize  a  three-wheel 
frame,  the  single  front  wheel  being  used  for  steering, 
while  others  employ  four  wheels,  the  two  smaller  front 
members  being  provided  with  some  operating  means  by 
which  the  course  of  the  machine  can  be  changed  at  the 
will  of  the  operator. 

Selection  of  Power  Plant. — The  type  and  size  of 
engine   needed    depends    on    many    varying    conditions. 


30°  Angle  with  Base 


One  in  2  or  50  Percent 


One  in  3  or  33% Percent 
One  in  4  or  25  Percent 


One  in  5  or  20  Percent 


One  in  70  or  JO  Percent 


0ne-in~T5-or-62/%  Percent 


One  in  20  or  5  Percent 


WOO  Feet 


Fig.  11. — Diagram    Showing    Method    of    Calculating    Grade 
Percentage. 

The  weight  of  the  tractor  and  its  capacity  are  the  first 
things  to  be  considered.  The  purpose  for  which  the 
tractor  is  intended  and  the  nature  of  the  country  in  which 
it  is  to  be  operated  are  also  factors  of  some  moment. 
Another  important  point  is  the  proposed  selling  price. 
One  would  not  expect  to  find  a  highly  refined  and  expen- 
sively built  motor  on  a  light  or  cheap  tractor.     Then 


The  Modern  Gas  Tractor  65 

again  there  would  be  nothing  gained  by  installing  an 
engine  of  large  capacity  in  a  machine  built  only  for 
relatively  light  work.  If  the  tractor  is  a  type  that  is 
likely  to  be  used  by  the  farmer  of  comparatively  small 
means,  the  engine  should  be  a  simple  one  that  will  be 
easily  understood  and  cared  for,  without  too  much 
trouble  or  expense.  Single-cylinder  engines  are  invari- 
ably used  on  low-powered  machines.  The  two  and  three- 
cylinder  motors  are  used  on  machines  of  moderate 
capacity,  while  the  four-cylinder  power  plant  is  installed 
in  the  highest  types  of  construction. 

Power  Needed  for  Hauling. — A  tractor  used  for 
hauling  purposes  does  not  need  to  be  as  powerful  as  one 
used  in  ploughing  or  breaking  because  of  the  difference 
in  draft  required  by  wheeled  vehicles  and  ploughs.  The 
tractive  effort  on  various  surfaces,  which  means  the 
amount  of  pull  or  push  necessary  to  move  wheeled 
vehicles  on  level  roads  as  given  by  Norris  follows: 

On  rails  or  plates 5.16  pounds  per  ton  weight 

Asphalt  or  hardwood 12.24      "  "     "       " 

Macadam 30.60      "  "     "       " 

Loose  gravel 150  to  200       "  "     "       " 

Sand 400         "  "     "       " 

From  the  foregoing,  it  will  be  seen  that  the  better  the 
surface  of  the  highways  over  which  the  load  is  hauled, 
the  less  the  amount  of  power  needed  to  move  a  definite 
weight.  If  it  is  necessary  to  haul  a  wagon  train,  weigh- 
ing ten  tons  over  a  macadam  road,  it  would  require  a 
draft  of  306  pounds.  To  move  the  same  weight  through 
sand  will  take  4,000  pounds  draft.  We  have  seen  that  a 
horse-power  was  equivalent  to  a  draft  of  approximately 
187  pounds  at  the  rate  of  two  miles  per  hour.  In  the 
first  case,  where  the  highway  surface  is  good,  a  drawbar 
pull  equivalent  to  that  exerted  by  two  horses  would  be 


66  The  Modern  Gas  Tractor 

sufficient  to  pull  ten  tons.  A  5  to  6  horse-power  tractor, 
if  properly  designed  would  be  adequate  to  move  this 
load,  provided  that  there  were  no  grades  or  stretches 
of  unfavorable  highway  to  be  encountered.  At  the  other 
hand  where  the  road  conditions  were  poor  a  pull  equiva- 
lent to  that  exerted  by  twenty  horses  would  be  needed 
and  a  very  efficient  tractor  equipped  with  a  35  or  40 
horse-power  motor  would  be  called  for. 

Other  factors  besides  the  condition  of  road  surfaces 
must  be  given  consideration.  The  factor  of  wind  resist- 
ance, which  is  so  important  in  figuring  power  required 
of  motor  cars,  locomotives  or  other  rapidly  moving 
vehicles  can  be  neglected,  but  the  effect  of  velocity  and 
gradient  must  be  considered  in  this  connection.  The 
relations  of  velocity  and  gradient  on  traction  will  be  con- 
sidered fully  later. 

Energy  Absorbed  by  Ploughs. — If  the  tractor  is  to 
be  used  for  breaking  and  ploughing  it  will  have  to  be  a 
powerful  one  if  it  is  to  do  an  amount  of  work  worth  while. 
Soils  differ  greatly  in  their  cohesive  properties  and  the 
amount  of  draft  required  to  operate  a  single  plough 
share  will  vary  within  wide  limits.  The  average  draft  of 
ploughs  as  determined  in  an  old  English  test  for  a  furrow 
5  inches  deep  by  9  inches  wide  made  in  five  different  soils 
was  as  follows: 

Loamy  sand 227  pounds 

Sandy  loam 250  pounds 

Moory  soil 280  pounds 

Strong  loam 440  pounds 

Blue  clay 661  pounds 

This  represents  an  extreme  range  of  194  per  cent.  One 
heavy  horse  would  be  needed  to  pull  a  plough  in  sandy 
loam  and  in  doing  this  he  would  be  exerting  a  draft, 
having  a  value  greater  than  one  horse-power.    A  team  of 


The  Modern  Gas  Tractor  67 

two  heavy  horses  would  be  needed  to  pull  the  shares 
through  strong  loam,  while  in  ploughing  the  blue  clay, 
three  heavy  or  four  light  horses  would  be  required  to 
pull  the  plough  continuously  for  a  working  day. 

Fifty-seven  tests  in  the  varying  soils  of  Missouri  gave 
an  average  draft  of  5.26  pounds  per  square-inch  area  of/ 
the  cross  section  of  the  furrow  slice  turned.  Seven  trials 
in  clover  gave  an  average  of  6.47  pounds  per  square  inch, 
while  six  in  oat  stubble  averaged  4.68  pounds.  Plough- 
ing in  virgin  gumbo  sod  requires  a  draft  of  13.75  to  16.3 
pounds  per  inch.  The  shape  of  the  plough,  the  weight, 
and  the  adjustment  must  all  be  taken  into  consideration 
as  well  as  the  depth  and  angle  of  the  cut.  The  situation 
may  be  summed  by  sa3ring  that  for  ordinary  widths  and 
depths  of  ploughing,  the  draft  per  square  inch  of  cross- 
section  ranges  from  a  minimum  of  three  pounds  in  sandy 
soil  to  seven  or  eight  in  clay,  six  or  seven  in  tame  clover 
sod,  and  ten  to  fifteen  pounds  turning  the  sod  of  the  vir- 
gin prairie.  The  draft  of  a  6xl4-inch  furrow  would  thus 
present  an  extreme  range  of  from  250  to  900  pounds, 
while  400  to  500  pounds  is  given  as  an  average  for  old 
land  in  the  middle  West. 

From  the  foregoing  it  will  be  evident  that  in  ploughing 
the  full  capacity  of  a  tractor  must  be  used.  A  30  horse- 
power tractor,  which  delivered  50  per  cent,  of  its  brake 
horse-power  or  15  horse-power  at  the  drawbar  would 
exert  a  pull  equivalent  to  2,810  pounds  at  the  rate  of  two 
miles  per  hour.  In  soil  requiring  a  draft  of  200  pounds 
per  plough  it  could  pull  a  fourteen-bottom  gang,  while 
in  exceptionally  heavy  soil,  requiring  a  draft  of  500 
pounds  per  ploughshare  its  capacity  would  be  but  a  six- 
bottom  gang.  It  will  be  seen  that  the  lighter  tractors 
having  comparatively  low-powered  engines  cannot  be 
used  as  economically  as  the  larger  ones  for  extensive 


68  The  Modern  Gas  Tractor 

ploughing,  though  they  are  practical  for  hauling  pur- 
poses, or  for  ploughing  on  small  farms. 

Power  Delivery  Under  Belt. — Most  traction  engines 
are  provided  with  a  pulley  by  which  the  motor  may  be 
coupled  to  any  form  of  machinery  that  can  be  driven  by 
a  belt.  In  this  work  practically  the  entire  brake  horse- 
power of  the  motor  is  available,  as  there  is  but  little  loss 
in  transmission.  When  it  is  used  for  traction  purposes 
part  of  the  power  is  being  used  in  moving  the  machine 
over  the  ground  and  part  is  being  lost  in  friction  in 
change  speed  and  driving  gearing.  An  engine  that  may 
deliver  30  horse-power  under  belt  would  not  deliver  more 
than  15  horse-power  at  the  drawbar  under  ordinary  con- 
ditions. 

Why  Proper  Distribution  of  Weight  is  Essen= 
tial. — To  get  the  largest  proportion  of  power  at  the 
drawbar  the  gas  tractor  designer  is  forced  to  consider  a 
number  of  important  conditions.  First,  the  engine  must 
be  strong  and  durable  and  the  friction  losses  through 
gears  and  shafting  must  be  reduced  to  a  minimum. 
Second,  the  design  of  the  machine  and  the  distribution 
of  weight  must  allow  the  engine  to  travel  over  a  great 
variety  of  soils. 

The  weight  must  be  so  distributed  and  carried  that  it 
will  consume  the  least  possible  amount  of  power  to  drive 
the  engine.  The  successful  traction  engine  must  be  capa- 
ble of  running  over  wet,  and  sometimes  muddy  ground, 
over  soft-ploughed  ground,  or  over  rough  field  surfaces. 
Every  horse-power  that  is  used  to  move  the  engine  is 
lost  and  only  that  available  at  the  drawbar  can  be 
counted  in  traction  work.  The  engine  designer  should 
consider  concentrating  the  weight  of  the  engine  where 
it  can  be  carried  to  best  advantage.  If  the  bulk  of  the 
weight  is  placed  at  the  center  of  the  frame  so  the  load  is 


The  Modern  Gas  Tractor  69 

carried  on  both  front  and  rear  axles,  the  amount  of 
power  delivered  at  the  drawbar  is  greatly  reduced  unless 
the  machine  is  a  four-wheel  drive  or  other  special  design. 

The  front  wheels  should  not  carry  any  more  load  than 
will  hold  them  in  contact  with  the  ground  with  sufficient 
pressure  to  insure  positive  steering.  The  smaller  the 
front  wheels  are  in  diameter  and  the  more  weight  carried 
by  them  the  greater  the  amount  of  power  it  requires  to 
force  them  ahead  and  the  more  difficult  it  is  to  control 
the  tractor. 

In  order  to  secure  the  greatest  tractive  efficiency  the 
greater  part  of  the  weight  should  be  carried  over  the 
rear  axle.  The  engine  should  be  placed  at  such  a  point 
that  the  front  end  will  not  be  overloaded  or  the  frame 
stressed  unduly.  When  the  motor  is  placed  parallel  with 
the  frame  and  when  the  bulk  of  the  gearing  is  carried  by 
the  rear  axle  the  greater  portion  of  the  strain  due  to 
weight  and  vibration  will  pass  directly  to  the  ground. 
The  degree  of  adhesion  between  the  rear-driving  mem- 
bers and  the  road  or  field  surface  depends  upon  the 
amount  of  weight  that  keeps  them  in  contact  with  the 
ground.  It  should  not  be  inferred  that  tractors  having 
the  engine  placed  in  front  or  in  the  middle  of  the  frame 
are  not  practical,  as  many  of  these  have  given  exception- 
ally good  results  in  practice. 

Influence  of  Weight  on  Traction. — When  a  motor- 
propelled  vehicle  travels  on  a  level  course  its  tendency 
to  forward  motion  is  resisted  by  three  main  items.  The 
most  important  of  these  is  the  rolling  resistance  at  the 
point  of  contact  of  the  wheels  with  the  ground.  Of  the 
other  two,  the  friction  in  the  rear  axle  and  driving 
mechanism  and  the  air  resistance;  the  influence  of  the 
latter  may  be  neglected  in  such  slow-moving  vehicles  as 
tractors.    If  the  vehicle  is  travelling  up  a  grade  the  power 


70  The  Modern  Gas  Tractor 

required  to  lift  the  weight  up  the  incline  should  also  be 
considered.  The  road  resistance,  as  we  have  seen,  de- 
pends to  some  extent  on  the  character  of  the  road  sur- 
face, but  another  factor  is  the  diameter  of  the  wheels 
and  the  speed  at  which  the  vehicle  travels.  In  the  table 
previously  given,  we  have  seen  that  on  a  good  macadam 
road  a  pull  of  30.6  pounds  would  move  a  ton,  therefore 
the  heavier  the  tractor  the  greater  the  amount  of  power 
needed  to  overcome  the  resistance  of  the  road.  The 
horizontal  effort  required  to  pull  a  tractor  up  a  grade  is 
equal  to  about  1  per  cent,  of  its  weight  for  each  per  cent, 
of  the  grade.  If  we  have  a  tractor  weighing  10,000 
pounds  and  we  wish  to  pull  it  up  a  10  per  cent,  grade  it 
will  require  a  pull  equal  to  10  per  cent,  of  the  weight  or 
1,000  pounds.  This  added  to  the  traction  resistance  of 
30.6  pounds  per  ton  means  that  an  added  pull  of  153 
pounds  must  be  considered  in  connection  with  the 
amount  of  force  needed  to  climb  the  grade.  Obviously 
a  lighter  tractor  would  not  require  so  much  power  on 
grades  and  could  be  operated  by  an  engine  of  less  power. 
At  the  same  time  as  the  amount  of  adhesion  between  the 
wheels  and  the  ground  would  be  less  in  case  of  the  light 
machine,  its  traction  capacity  would  be  reduced  in 
direct  proportion. 

It  will  be  apparent  that  there  are  extremes  which 
the  careful  designer  will  avoid.  A  heavy  machine  with 
an  inadequate  power  plant  or  with  an  inefficient  system 
of  transmission  will  not  be  practical  because  it  could  not 
surmount  grades  and  would  not  have  the  range  of  work 
that  its  size  would  indicate.  At  the  other  hand  the  mis- 
take can  be  made  of  using  too  large  a  power  plant  in  a 
light  machine.  This  would  mean  that  while  it  would 
prove  to  be  a  good  hill  climber  or  have  a  capacity  for 
hauling,  it  would  not  have  weight  enough  to  insure  the 


The  Modern  Gas  Tractor 


71 


delivery  of  its  full  drawbar  horse-power  on  account  of 
the  limits  in  traction  imposed  by  the  light  weight  on  the 
rear  wheels.  This  is  overcome  in  some  constructions, 
notably  in  the  combined  self-contained  ploughing  and 
traction  machines  where  the  ploughs  are  carried  under 
the  frame  of  the  tractor  in  such  a  way  that  the  resistance 
offered  by  the  earth  to  the  cutting  action  of  the  plough 
will  hold  the  wheels  firmly  against  the  ground  and  thus 
increase  the  available  tractive  effect.  In  this  way  a 
light  machine  that  would  not  be  adequate  to  pull  a 
trailer  plough  will  handle  the  ploughs  provided  as  a  part 
of  its  structure  with  ease. 

Influence  of  Road  or  Field  Surface  on  Traction. — 
We  have  seen  by  the  table,  previously  considered  that 
the  draft  required  to  haul  wagons  varied  according  to 
the  nature  of  the  road  surface.  The  harder  the  surface 
over  which  the  wheels  rolled,  the  less  the  amount  of  pull 
needed  to  keep  the  vehicle  in  motion.     The  following 


Grade. 

Ft.  per 

Per 

mile. 

cent. 

Level 

0 

53 

1 

106 

2 

158 

3 

211 

4 

21)4 

5 

422 

8 

528 

10 

634 

12 

792 

15 

Macadam 
Road. 


2,135 
2,405 
2,675 
2,945 


Firm  Earth 

Road  Not 

Sticky. 


II. P.   Draft  H.P. 


3,21516 


3,485 
4,295 
4,835 
5,375 

6,185 


34  6 


500  12 
770  14 
040  15 
310  16 
58018 
850  19 
660  23 
200  26 
740  29 
550  33 


Soft 
Muddy 
Road. 


Draft 


650 
,920 
190 
460 
730 
000 
810 


Soft  Field. 


H.P.  Draft 


350  27 
890  29 
,700  33 


040 
310 
580 
850 
120 
390 
200 
740 
•_N) 
090 


H.P. 


15.40 

16.77 
18.14 
19.51 
20.88 
22.44 
26.35 
29.08 
31.82 
35.93 


72  The  Modern  Gas  Tractor 

table  gives  the  horse-power  and  draft  required  to  pull  a 
133^2-tons  tractor  over  various  grades  and  road  surfaces 
at  a  net  speed  of  1.9  miles  per  hour  and  shows  clearly 
the  effect  of  varying  road  and  field  surfaces  on  traction. 

Brief  study  of  the  table  will  show  that  the  varia- 
tion in  draft  for  different  road  surfaces  is  not  as  great  as 
for  wagons.  The  amount  of  pull  needed  ranges  from 
160  to  225  pounds  per  gross  ton.  These  figures  are 
higher  than  are  usual  with  wagons  and  may  be  ascribed 
to  the  greater  internal  friction  existing  between  the  vari- 
ous parts  of  the  mechanism.  In  a  test  a  ton  of  engine 
weight  required  a  draft  20  per  cent,  greater  than  the 
same  weight  of  wagon  and  load.  If  a  constant  figure  or 
allowance  for  the  friction  of  gearing  could  be  made  and 
substracted  from  the  draft  per  gross  ton  in  each  case  the 
difference  in  draft  due  to  road  surface  would  be  more 
strongly  emphasized.  As  it  is,  it  required  from  40  per 
cent,  to  50  per  cent,  more  power  to  pull  the  tractor  over 
soft-field  surface  than  it  did  over  macadam  road. 

Effect  of  Grades  on  Traction. — On  grades  the  in- 
ternal friction  and  ground  resistance  are  constant  fac- 
tors, providing  that  the  road  surface  on  the  gradient  is 
the  same  as  obtains  on  the  level  highway.  In  the  above 
table  the  variation  between  the  power  needed  to  move  a 
tractor  on  the  level  and  on  grade  is  due  to  the  effort 
expended  in  lifting  the  tractor.  Under  actual  service 
conditions,  the  internal  friction  to  be  allowed  for  would 
depend  entirely  upon  the  design  of  the  transmission 
mechanism  and  the  care  taken  to  keep  the  various  bear- 
ings, gears,  etc.,  well  lubricated  and  in  line. 

An  authority  has  stated  that  allowing  250  pounds  of 
resistance  per  ton  of  weight  would  not  be  too  much  in 
estimating  the  power  required  to  move  the  average 
tractor  over  an  ordinary  road.     Each  per  cent,  of  grade 


The  Modern  Gas  Tractor  73 

adds  1  per  cent,  of  the  tractor  weight  to  the  resistance 
or  20  pounds  per  ton.  For  example,  it  is  desired  to  esti- 
mate power  required  to  move  a  12-ton  tractor  up  a  10 
per  cent,  grade  at  2.5  miles  per  hour.  The  following 
equations  show  the  method  of  determining  this: 

(12x250)  +(12 Xl0x20)  =  5,400  pounds. 
5,400x2.5      13,500 


375  375 


=  36  horse-power. 


Considerable  difference  of  opinion  obtains  as  to  the 
methods  of  calculating  grade  percentages  and  some  con- 
fusion may  exist  in  the  mind  of  a  non-technical  reader 
regarding  the  difference  between  the  percentage  and 
angle  of  a  grade.  A  diagram  is  given  at  Fig.  11,  which 
shows  the  method  in  vogue  graphically.  If  it  is  assumed 
that  the  base  of  the  triangle  represents  a  line  1,000  feet 
long  and  that  the  first  sloping  line  represents  a  road 
having  a  rise  that  brings  it  50  feet  above  the  starting 
point  this  would  be  considered  as  a  rise  of  50  feet  in 
1,000  feet  or  one  in  twenty  and  would  correspond  to  a 
5  per  cent  grade.  The  rise  is  based  on  the  length  of  the 
base  line  not  of  the  hypothenuse  of  the  triangle,  which 
is  represented  by  the  inclined  roadway.  A  grade  which 
represents  100  per  cent,  corresponds  to  an  angle  of  but 
45  degrees  and  not  90  degrees,  or  perpendicular,  as  is 
commonly  supposed.  When  the  grade  becomes  steep 
enough  so  the  angle  of  inclination  is  over  30  degrees, 
gravitjr  overcomes  traction  and  some  positive  method 
of  drive  such  as  gear  wheels  running  on  toothed  tracks  are 
necessary  to  climb  greater  gradients  than  30  degrees  angle. 

The  following  table  gives  the  percentages  and  corres- 
ponding angles  of  inclination  for  gradients  ordinarily 
met  with,  except  in  the  very  mountainous  sections  of  the 
countrv: 


74 


The  Modern  Gas  Tractor 


TABLE    OF    GRADIENTS. 


Grade. 

Equal  to 

Rise  or  Fall  in 

Angle  of 

One  Mile,  Feet. 

Per  Cent. 

Units. 

20 

1  in  5 

11°        19' 

1,056 

17 

1  in  6 

9°   26' 

880 

14 

1  in  7 

8°  09' 

754 

12.5 

1  in  8 

7°  08' 

635 

11 

1  in  9 

6°    17' 

586 

10 

1  in  10 

5°   43' 

528 

9 

1  in  11 

5°    11' 

480 

8 

1  in  12 

4°   46' 

440 

7.75 

1  in  13 

4°   24' 

406 

7 

1  in  14 

4°   05' 

337 

6.5 

1  in  15 

3°   49' 

352 

6.25 

1  in  10 

3°   35' 

330 

6 

1  in  17 

3°   22' 

310 

5.5 

1  in  18 

3°    11' 

293 

5 

1  in  20 

2° -52' 

204 

Types  of  Tractors. — The  various  constructions  that 
can  be  termed  "gas  tractors"  vary  from  the  small  self- 
propelling  lawn  mowers  to  the  heaviest  machines 
equipped  with  engines  of  over  100  horse-power.  Of  the 
many  types  of  tractors  offered  the  public  the  most  com- 
mon and  that  which  enjoys  the  widest  sale  is  the  medium 
capacity  outfit  that  will  handle  about  six  ploughs  as 
well  as  any  of  the  other  farm  machines  generally  used 
on  medium  sized  farms.  The  field  for  the  very  light 
tractor  is  not  a  large  one  inasmuch  as  these  are  suitable 
only  for  hauling  and  for  work  under  the  belt.  Their 
capacity  is  not  large  enough  to  make  them  profitable  in 
anything  except  the  lightest  forms  of  work.  While 
traction  engines  are  on  the  market  with  power  plants 
as  low  as  10  horse-power  they  are  not  as  practical  for 


The  Modern  Gas  Tractor  75 

general  service  as  those  which  have  twice  the  power  and 
cost  but  little  more.  In  some  special  classes  of  work  the 
light  tractor  has  a  field  but  in  general  the  practical  type 
is  seldom  equipped  with  less  than  a  20  horse-power 
engine. 

Tractors  have  been  designed  for  use  in  orchards  that 
are  moderately  light,  if  compared  to  the  large  machines 
used  on  the  prairie  farms  of  the  Middle  West.  They 
are  entirely  suited  for  the  work  they  are  to  do  and  give 
good  results  in  practical  use.  A  man  owning  a  small 
farm,  such  as  one  that  would  find  work  for  about  four 
horses  can  use  the  lighter  tractor  to  advantage,inasmuch 
as  it  will  do  all  the  ploughing  that  the  horses  will  and 
when  not  employed  in  the  field  the  engine  can  be  utilized 
in  all  of  the  various  duties  which  require  stationary 
power  where  horseflesh  could  not  be  used.  Tractors 
having  30  horse-power  engines  are  quite  common  and 
are  generally  used  in  road  work  as  well  as  on  medium 
sized  farms. 

Tractors  vary  in  type  at  present  just  as  widely  as  did 
automobiles  of  a  decade  ago.  Owing  to  the  infancy  of 
the  gas  'tractor  industry  there  has  been  no  attempt  at 
standardization  as  is  now  the  case  in  automobile  con- 
struction. Some  tractors  on  the  market  are  very  rough 
in  construction,  and  appear  to  have  been  evolved  by  a 
cut-and-try  method,  rather  than  attempting  to  follow 
any  definite  plan  or  design.  Others  show  evidence  of 
careful  thought  and  study  of  engineering  principles.  In 
some  of  the  cheaper  machines  cast  iron  is  widely  used  as 
a  material  of  construction.  Power  is  transmitted  through 
inefficient  cast  gears  which  are  exposed  to  the  dirt  and 
grit  of  the  field  and  which  can  never  be  adequately  lubri- 
cated. The  power  plants  are  heavy  stationary  engines 
and  the  entire  mechanism  is  inefficient  and  crude.     The 


7(i  The  Modern  Gas  Tractor 

machines  that  are  carefully  designed  use  steel  forgings 
instead  of  castings,  utilize  power  plants  of  the  automo- 
bile type,  employ  the  best  cut  steel  gearing,  thoroughly 
encased,  to  protect  it  from  the  dirt  and  well  lubricated 
to  insure  long  life  and  efficient  operation.  The  mechan- 
ism is  thoroughly  protected  from  the  elements  and  the 
control  members  are  conveniently  placed  so  that  they 
may  be  easily  handled  by  the  operator  . 

As  can  be> expected,  the  machines  using  the  best  con- 
struction and  materials  and  based  on  correct  engineering 
principles  are  more  costly  than  the  hastily  designed  and 
crudely  constructed  machines.  This  is  a  case  where 
first  cost  is  of  less  importance  than  after  cost  or  mainte- 
nance expense.  The  well-designed  machine  will  be  ser- 
viceable under  conditions  that  will  quickly  consign  the 
cheap  mechanism  to  the  scrap  heap.  The  farmer  who 
intends  to  purchase  a  tractor  should  look  into  the  con- 
struction and  engineering  features  of  the  various  types 
very  carefully  before  purchasing.  Many  who  condemn 
gas  tractors  as  impractical  pieces  of  machinery  do  so 
because  they  purchase  poorly  designed  machines,  either 
through  ignorance  of  mechanical  principles  or  because 
the  low  selling  price  proved  attractive.  A  farmer  would 
not  expect  the  amount  of  work  out  of  a  cheap  horse,  or 
in  fact,  any  farm  machine  that  he  would  get  out  of  the 
more  expensive  one.  As  a  rule  one  gets  no  more  than 
one  pays  for  and  this  applies  just  as  well  to  the  purchase 
of  a  gas  tractor  as  to  a  mowing  machine,  cultivator,  or 
any  other  farm  implement. 

Traction  Engines  for  Small  and  Medium  Sized 
Farms. — Many  farmers  are  of  the  opinion  that  traction 
engines  are  only  suitable  for  large  farms  where  extensive 
areas  must  be  cultivated.  This  is  a  misconception  that 
is  not  borne  out  by  the  actual  facts.     Even  if  the  area 


The  Modern  <1as  Tractor  77 

under  cultivation  is  not  a  large  one  power  traction  would 
permit  of  more  thorough  soil  tilling  than  is  possible  with 
horses.  On  every  farm  forage  plants  must  be  chopped, 
corn  shredded  and  shelled,  wood  sawing  must  be  done 
during  the  winter  months,  and  water  must  be  supplied 
in  abundance  at  all  times  in  the  year.  Engine  power  is 
the  only  practical  energy  for  this  work. 

In  many  districts,  a  great  advanatge  can  be  gained 
from  deep  ploughing,  which  is  necessary  to  liberate  the 
fertility  of  new  soil.  Deep  ploughing  is  not  possible  with 
horse-power  because  the  average  farmer  who  has  humane 
instincts  hesitates  to  plough  as  deep  as  may  be  desirable 
through  fear  of  cruelly  abusing  his  animals.  It  will  be 
seen  that  even  the  small  or  medium  sized  farm  can  use  a 
tractor  to  advantage  in  ploughing  work,  providing  that 
it  can  be  adapted  to  other  labors  at  periods  when  plough- 
ing is  over.  Disking  and  thorough  harrowing  are  neces- 
sary to  prepare  a  good  seed  bed  and  proper  pulverization 
of  the  soil  is  necessary  to  retain  moisture.  The  advan- 
tage of  an  engine  on  a  small  farm  is  that  it  can  do  this 
work  as  well  as  ploughing  and  in  many  cases  the  same 
power  plant  to  which  ploughs  are  attached  will  do  the 
disking  and  harrowing  at  the  same  time. 

Many  of  the  smaller  farmers  are  just  beginning  to 
recognize  that  animal  power  is  slow  and  that  the  in- 
creased number  of  horses  made  necessary  by  the  modern 
methods  of  farming  are  not  only  expensive  in  first  cost 
but  necessitate  setting  aside  some  of  the  most  valuable 
land  for  raising  hay  and  grain  to  feed  the  animals.  A 
number  of  tractor  manufacturers  are  furnishing  medium 
weight  machines  equipped  with  30  horse-power  engines 
that  will  do  the  work  of  fifteen  horses  at  the  drawbar. 
These  have  been  designed  especially  to  meet  the  general 
demands  of  the  smaller  corn  belt  farms  of  the  Middle 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  79 

West.  Such  a  machine  will  pull  a  four  bottom  gang  in 
breaking  and  six  in  ploughing.  From  ten  to  fourteen 
acres  a  day  can  be  ploughed  and  harrowed  in  one  opera- 
tion. These  machines  are  easily  handled  as  they  will 
turn  short  and  work  closely  into  the  corners  of  the  field. 
It  is  claimed  that  two  good  sized  boys  with  a  machine 
of  this  character  will  easily  do  the  same  amount  of  work 
that  twelve  horses  and  four  men  will  do  in  a  day.  Such 
a  tractor  will  run  up  to  a  32-inch  separator  and  will 
operate  corn  huskers,  shellers,  shredders  or  any  similar 
machinery.  Any  farmer  working  160  acres  can  use  such 
an  outfit  with  profit. 

Even  the  small  farmer  can  use  one  of  the  combined 
self-contained  ploughing  machines  to  advantage  as 
there  are  some  on  the  market  that  cost  less  than  four 
horses  and  that  will  accomplish  more  work  of  an  all- 
around  nature  than  the  animals  will.  Such  a  machine 
is  shown  at  Fig.  12  and  has  the  plough  hung  under  the 
operator's  seat  and  about  midway  of  the  frame.  With  a 
16-inch  plough  a  man  can  do  as  much  work  as  he  would 
with  four  horses,  as  .the  machine  will  travel  on  the  low 
gear  as  fast  as  a  good  team  will  ordinarily  walk  and  will 
be  much  faster  on  the  high  gear.  The  low  ratio  of  speed 
is  used  for  ploughing  and  other  heavy  work,  requiring 
considerable  draft,  and  the  high  gear  is  employed  for 
cultivating,  hauling  a  light  load,  or  travelling  on  the 
road. 

For  ploughing  the  share  is  set  inside  of  the  frame 
with  the  front  end  of  the  beam  .attached  to  a  malleable 
casting  under  the  front  end  of  the  frame.  The  driver 
sits  directly  over  the  plough,  which  is  in  full  view  at  all 
times.  The  right-hand  steering  wheel  runs  in  the  fur- 
row ahead  of  the  plough  and  the  traction  wheel  in  the 
next  furrow  behind  the  plough,  thus  putting  two  wheels 


80 


Tin:  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  M 

carrying  seven-eights  of  the  load  in  the  bottom  of  the 
furrows  where  the  ground  is  solid.  The  makers  claim 
that  it  takes  less  power  to  push  the  machine  under  these 
conditions  than  if  running  in  loose  soft  stubble  ground 
or  over  rough  prairie  sod.  This  motor  machine  will  pull 
a  seeder  or  drill  in  conjunction  with  a  two-section  har- 
row, thus  doing  the  work  of  two  men  and  two  teams  on 
the  small  farm.  It  will  pull  a  six  or  seven-foot  d  sk  har- 
row, which  requires  three  or  four  horses  and  do  it  at  less 
expense.  In  addition  to  the  work  in  the  field  it  will  run  a 
medium  sized  ensilage  cutter  for  filling  a  silo  and  will 
furnish  power  for  all  the  other  farm  tasks  that  can  be 
performed  by  an  engine. 

This  machine  is  recommended  for  orchard  cultivation 
because  it  is  low  enough  to  permit  it  to  get  around  under 
the  low  branches  of  the  trees.  Many  orchardists  do  not 
care  to  handle  horses  around  their  trees  because  they 
are  awkard  and  need  constant  watching  to  prevent  them 
from  nibbling  at  the  young  shoots  and  nipping  off  the 
tops  of  small  trees.  A  machine  of  this  size  also  has  the 
advantage  that  it  may  be  easily  stored  in  any  shed  or 
barn  that  will  house  the  ordinary  horse-drawn  vehicle. 
Many  of  the  odd  jobs  that  need  to  be  done,  such  as  haul- 
ing a  load  of  manure  or  hay  can  be  accomplished  with 
this  machine. 

The  convenience  and  ease  in  handling  makes  a  tractor 
of  this  size  practical  for  many  things  that  the  larger 
ones  could  not  be  used  for.  It  is  as  easy  to  control  as  a 
horse  and  as  it  will  back  up  as  well  as  go  forward  it  can  be 
moved  around  in  nooks  and  corners  where  a  horse  and  wag- 
on outfit  could  be  handled  only  with  difficulty.  Another 
form  of  self-contained  ploughing  machine  with  the  parts 
clearly  indicated  is  shown  at  Fig.  13.  This  has  larger 
capacity  and  is  a  more  powerful  mechanism  than  that 


82 


The  Modern  (Ias  Tractor 


previously  described.  Three  ploughs  are  provided  under 
the  frame,  these  being  controlled  by  the  operator  sitting 
above  them.  They  may  be  removed  and  a  road  scraper 
attached  under  the  machine  as  at  Fig.  14,  or  this  attach- 
ment can  be  dispensed  with  and  the  machine  used  for 
general  hauling  and  power  purposes. 


Fig.  14. — The    Hackney    Auto    Plough    With     Road    Scraper 
Attachment    a  Practical  Machine  for  Highway  Work. 

Large  Capacity  Tractors. — The  first  class  of  gas 
tractors,  in  which  those  having  power  plants  ranging 
from  18  to  30  horse-power  are  included,  are  capable  of 
handling  three  or  four  ploughs  in  ordinary  sod  breaking 
and  are  used  on  medium  sized  farms.  The  second  class 
is  provided  with  engines  of  40  to  50  horse-power  and  will 
handle  up  to  seven  ploughs  in  heavy  work.  This  and  the 
largest  class,  which  ranges  from  60  to  75  horse-power 
with  the  ability  to  pull  from  eight  to  ten  ploughs  under 
the  same  conditions  are  used  on  the  larger  farms.  Some 
large  machines  have  been  made,  which  will  pull  twelve 
ploughs,  but  these  have  not  been  sold  as  extensively  as 
the  medium  weight  outfits  because  they  are  so  large  and 
powerful   that  they  cannot   be   used   on   anything  but 


The  Modern  Gas  Tractor  83 

large  farms  to  advantage.  These  machines  require  two 
men  to  handle  them,  one  to  run  the  engine  and  the  other 
to  handle  the  load  of  ploughs.  While  costly  to  purchase 
and  operate,  they  have  such  a  large  capacity  that  they 
are  economical  if  operated  at  capacity. 

The  very  large  machines  have  some  disadvantages. 
Owing  to  their  weight  they  tend  to  pack  the  ground  and 
it  is  only  in  ploughing  that  their  full  capacity  can  be 
used  to  advantage.  Many  operators  of  large  farms 
prefer  to  divide  the  initial  investment  required  for  one  of 
these  massive  machines  and  purchase  a  number  of  the 
medium  sized  tractors,  even  though  it  takes  more  help 
to  operate  them,  and  do  the  same  amount  of  work  that 
the  large  machine  will  perform.  It  is  safer  to  have  the 
work  divided  among  a  number  of  machines  rather  than 
employing  an  extremely  large  one,  because  failure  of 
one  of  several  tractors  will  not  prove  so  serious  as  when 
the  one  large  machine  refuses  to  operate.  Except  in 
unusual  cases,  even  the  operators  of  very  large  farms 
prefer  the  medium  class  tractor  to  the  heavy  types. 

Parts  of  Typical  Tractors  Outlined. — The  plan 
view  presented  at  Fig.  15  shows  clearly  the  various  parts 
of  a  typical  gas  tractor  and  their  relation  to  each  other. 
The  machinery  is  carried  on  a  frame  made  of  structural 
steel  supported  at  the  front  end  by  an  axle  of  the  pivoted 
type,  having  steering  knuckles  to  which  the  front  wheels 
are  attached.  In  this  construction  the  axle  does  not 
move,  but  the  wheels  can  assume  the  angle  required  for 
describing  a  curve,  because  the  tiebar  which  joins  the 
steering  arm  actuates  both  wheels  in  unison.  The  front 
wheels  of  a  tractor  of  conventional  design  are  always 
smaller  than  the  rear  members  because  they  are  gener- 
ally used  only  for  steering,  and  do  not  carrj'  a  large  pro- 
portion of  the  tractor  weight  in  most  constructions. 


84 


Front  Wheel 


\ 


The  Modern  Gas  Tractor 

Steering  Knuckle  Radiator 

Fan  Axie 


Cylinders 

Belt  Pulley 
—  Driving  Pinion 


Rear  Axle 


Draft  Bar  Change  Speed  Gears 


Fig.  15. — Parts  of  the  Pioneer  Tractor  Outlined. 


, 


Fro.  16-  SIDE  ELEVATION  HOLT  "CATERPILLAR"  TRACTOB  SHOWING  ALL  IMPORTANT  PARTS  AND  THE  RELATION  To  EACH  OTHER 


Crank  Bearing  Cap — long 

i    Side  Plate— Right 
Side  Plate— Left 
oil  Pump  Phut: 
Oil  Gauge 
Crank  Shaft  Timing  Gear 

Key  for  (Tank  shah  Timing  « 

Oun  Shaft  Timing  Gear 

Key  for  Cam  Shaft  Timing  « 
Cara8h""' 

Magne 

( iea'r  <  i 

Magnew 

Magneto  Shaft 
Magneto  Bracket 
Magneto  Coupling 
Magneto 
Tappet 

Tappet  Guide— High 
Tappet  Guide— Left 
Tappet  (luidi — CniM 
.    Breather 
Cylinder 


\L    Cam  Shaft  Etnl  Bnshu 


AN    Gear  Guard 


o  Shaft  Brocket 


HB    Cylinder  Gasket. 


lock 


BE    Cylinder  Head 

BF    Long  Stud  for  Cylinder  Head 

BG    short  Stud  for  Cylinder  Head 


BK   Valve  Stem  V 
BL    Valve  Stem8 


BQ  Push  Rod 

BR  Push  Rod  End 

BS  Water  Heads- 

BT  Water  Header  Stud 

BU  Priming  Cup 

BV  Spark  Plug 

mv  Pi  her  Tube 

UX  Fiber  Tube  Claim. 

BY  Exhaust  Manifold 

BZ  Inlet  Munif<Hd 

CA  Manifold  C1UI1|) 

OB  Manifold  St* 

<'»'  Butterfly  Can- 


OK  Governor  Spring 


*P    Fly  Wheel 


OS  Key  for  Cooling  Fan 

<  'T  Crank  S,haft 

CU  Key  for  Fly  Wheel 

DA  Friction  Retainer 


Ml)    Friction  Retain,  r  Kin- 


UK   Adjusting  Screw 
Ul,    Friction  Dog  Pin 
DM   Friction  Link 
DN   Friction  Link  Pin 
DO    Friction  Shifter  Pin 


DP    Friction  Lever— Left 

DV    Friction  Lever-  Extension 


DY    Gear  Case  Cover 


EH  Ball  Thrust  Bearing 

KI  Reverse  Clutch 

EJ  Reverse  Clutch  Shifter  Am 

EK  Reverse  Clutch  Shifting  V. 

EL  Reverse  Clutch  Lever 

EM  Reverse  Lever  Hand  «  Irip 

EN  Belt  Pulley  Shaft 

Et>  Belt  Pullev  Bearing 

EP  Belt  Pulley  Bearing  Cap 


Eli 


B.vel  Union  Shaft 


K\      Flange. i  (  '...upline  Hull' 
EZ     Bevel  Gear 
PA    Friction  Wheel 


FD    Pin  for  Frielii 


FK    Friction  Shifter  Ring 
FL    Friction  Shifter  Arm 


FP  Shifting  Link  Stop 

PQ  Rod  End-  Wide  Jaw 

PR  Left  shift  Rod 

FS  Right  Shift  Rod 

FT  <  tear  Supporting  Roller 

fit  Supporting  Rolf  i  Brat  I  et 


FV^   Supporting  Roller  Shaft 

>tli 
FY    Main  Friction  Bearing 
FZ     Main  Friction  Bearing  i  !ap 
GA    Shaft  End  Cap 
GB    Drive  Chain  Link 
GC    Drive  Chain  Pin 
GD   Chain  Sprocket— Right 
GE    Chain  Sprocket— Left 
GF    Spring  Driver — Right 
GG    Spring  Driver       l.efi 
i.  II    Spring  Driver  Key 
GI    Spring  Driver  Spring 
GJ      Main  Drive  Shaft 
GK  Center  Truss 
GL    split  Collar 
GM  Main  Drive  Shaft  Bearing 
gn  Track  Drive  Sprocket 

GO    Key  for  Track  Drive  Sprocket 
( i  P    Rear  Thrust  Rod  Bearing 
GO    Rear  Thrust  Rod  Bearing  Cap 


Track  Pin 
Track  Pin  Keeper 


GY    Rear  Thrust  Rod 


11  B     Front  Thrust   Rod  Nut 


hi     Roller  Fi- 


ll n  Gudgeon  Wedge 

Iio  Blank  Sprocket  Shaft 

HP  Blank  Sprocket   lie;inie: 

HQ  Blank  Sprocket  Bearing  (  !ap 

UK  Blank  Sprocket 

US  FrontTbn 


1IV    Steering  Wheel 


i  ring  Rod  Bearing 

HZ     Motor  Control  < .niadr.it. I 
I  \      Motor  Control  Lever 


IB     Coupling  Steering  Rod 

K  1      Steering  Worm 

ID     Steering  Gear  Worm  "  ■. 


It ;     Steering  Rod  Clamp 


1,1  Steering  Gfl 

1  K  Steering  '  iear  segment 

11,  Front  \\  I.e.  I     .. 

IM  Side  Holler  Bracket 

|\  Cast  Iron  Pipe 

lo  Front  Axle 


IR      Wheel  Huh 


i  \      Radiator  Head  ■ 


IV      Radiator  Tnhes 


jb     Radiator  Sight  Glow 
.jc    Radiator  I  lange 
JD    Pet  Cock 


The  Modern  <Ias  Tractor  85 

Mounted  at  the  front  end  of  the  frame  are  cooling  fan 
and  radiator.  The  latter  is  used  to  carry  a  supply  of 
water  for  cooling  the  engine  cylinders  and  also  to  cool 
the  heated  water  from  the  engine  that  is  pumped  through 
it.  This  member  forms  a  very  important  part  of  the 
cooling  system.  The  air  fan  placed  back  of  the  radiator 
is  positively  driven  by  gearing  from  the  engine  and 
serves  to  draw  a  blast  of  air  through  the  openings  of  the 
cooler,  and  abstract  the  heat  from  the  walls  of  the  tubes 
through  which  the  water  circulates. 

The  power  plant  in  this  case  is  carried  about  midway 
of  the  frame  and  is  composed  of  a  four-cylinder  gasoline 
engine,  having  opposed  cylinders  horizontally  disposed, 
the  crankshaft  of  the  motor  being  at  right  angles  to  the 
frame.  Beside  the  motor  fly-wheel  a  driving  pinion  is 
mounted,  this  communicating  with  the  main  shaft  of  the 
transmission  by  an  intermediate  drive  pinion,  which 
meshes  with  the  driving  pinion  on  the  engine  crankshaft 
and  with  a  large  gear  on  the  transmission  mainshaft.  A 
belt-pulley  is  mounted  outside  of  the  frame  on  the  crank- 
shaft extension,  this  enabling  one  to  obtain  power  from 
the  engine  for  running  various  machines.  A  clutch  is 
provided  on  the  engine  shaft,  so  the  driving  pinion  may 
be  put  in  action  or  so  the  belt  pulley  may  be  clutched  to 
the  shaft. 

When  the  driving  pinion  is  turning  with  the  shaft  it 
produces  motion  of  the  transmission  mainshaft  which  is 
a  square  member,  carrying  three  sliding  gears  actuated 
by  a  common  shifter  member.  When  the  smaller  of 
these  gears  is  meshed  with  the  medium  sized  gear  at- 
tached to  the  differential  gear  case  a  slow  speed  ahead 
is  obtained.  When  the  gears  are  in  the  position  shown 
a  reverse  motion  is  obtained.  The  gear  on  the  main 
shaft  is  driving  an  intermediate  pinion  at  the  bottom  of 


86 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  Xi 

the  gear  case  which  in  turn  operates  the  largest  gear  on 
the  differential  casing.  When  the  largest  gear  on  the 
main  shaft  is  engaged  with  the  smallest  gear  on  the  dif- 
ferential box  the  high  speed  forward  is  obtained. 

The  differential  mechanism,  the  action  of  which  will 
be  described  more  in  detail  later,  is  necessary  with  all 
forms  of  self-propelling  vehicles  where  two  wheels  are 
driven  from  a  common  source.  Without  it  the  auto- 
mobile or  traction  engine  would  not  be  practical.  It 
permits  the  outer  wheel  to  revolve  faster  than  the  inner 
wheel  when  the  machine  is  turning  a  corner.  Leading 
from  the  differential  gear  are  two  shafts  which  carry  bull 
pinions  at  their  outer  ends.  These  engage  with  the  bull 
gears  which  drive  the  large  rear  wheels  of  the  tractor. 
The  rear  axle  is  a  substantial  fixed  member  on  which  the 
rear  wheels  revolve. 

The  cut  previously  described  shows  clearly  the  rela- 
tion of  the  power  plant  to  the  driving  wheels  and  out- 
lines the  various  gears  through  which  the  engine  power 
is  transmitted  and  by  which  the  engine  speed  of  four  or 
five  hundred  revolutions  per  minute  is  reduced  to  a  few 
revolutions  per  minute  of  the  driving  wheels.  The  side 
elevation  outlined  on  the  large  folding  plate,  Fig.  16, 
outlines  clearly  all  the  parts  of  a  large  capacitj'  tractor 
of  the  Caterpillar  tread  type.  As  the  key  clearly  defines 
the  various  parts  their  functions  will  be  readily  apparent. 

Some  Distinctive  Designs. — Special  designs  of  trac- 
tors have  been  devised  to  do  work  more  efficiently  than 
the  conventional  forms.  For  example,  for  overcoming 
the  disadvantage  of  very  soft  ground  no  device  appears 
to  be  more  successful  than  the  substitution  of  a  Cater- 
pillar tread  for  the  ordinary  type  of  traction  wheel.  A 
tractor  of  this  form  is  shown  at  Fig.  17  and  has  proved 
very    satisfactory    in    practice.      It    has    been    used    on 


88  The  Modern  Gas  Tractor 

swampy  ground  where  wheel  tractors  could  not  turn  a 
wheel  and  it  has  found  a  field  of  usefulness  in  hauling 
lumber  on  the  soft  snow-covered  roads  of  the  great 
Canadian  forests.  This  idea  is  several  generations  old 
but  it  is  only  recently  that  tractors  having  this  type  of 
transmission  have  been  put  on  the  market  in  large  num- 
bers. 

The  weight  of  the  tractor  is  supported  on  steel  rollers, 
which  run  on  the  inside  of  a  continuous  belt  made  of 
steel  plates,  joined  together  so  they  can  run  around 
wheels  at  the  front  and  rear  of  the  truck.  This  means 
that  the  tractor  lays  a  track  and  picks  it  up  as  fast  as  it 
is  no  long  needed.  The  front  of  the  tractor  is  supported 
by  a  single  wheel,  so  under  actual  working  conditions 
nearly  all  the  weight  of  the  tractor  is  carried  on  the  rear 
where  it  is  distributed  over  such  an  area  of  ground  eon- 
tact  that  the  weight  carried  is  but  five  or  six  pounds  per 
square  inch  as  compared  to  the  forty  to  ninety  pounds 
ordinarily  supported  by  each  square  inch  of  wheel  sur- 
face in  contact  with  the  ground  on  the  conventional  type 
of  tractor.  This  Caterpillar  tread  and  driving  mechanism 
are  described  in  detail  in  the  chapter  dealing  with  the 
tractor  frame,  wheels  and  axles. 

Some  experiments  have  been  made  abroad  with  power- 
propelled  machines  carrying  a  large  drum  at  the  rear 
driven  by  chain  connection  from  the  rear  wheels.  These 
drums  carry  a  number  of  teeth  or  small  spades,  which 
dig  into  the  ground  and  break  up  the  surface  in  the  same 
way  that  a  multitude  of  picks  would  do.  Other  forms 
have  rotary  ploughs  carried  at  the  rear  end. 

A  tractor  that  has  been  well  received  by  many  farm- 
ers is  built  on  the  order  of  the  motor  truck  used  in 
cities  for  hauling  merchandise.  It  will  carry  a  load  of 
three  tons  in  the  wagon  bed  with  which  it  is  provided 


The  Modern  Gas  Tractor 


89 


.2  Q 


E-<    g 


|5 

o 

o 

(In 

— 

>> 

-.1 

s-. 

5j 

o 

= 

H 

ia 

at 

p3 

7 

0) 

O 

1* 

cm 

o 

CD 

p-f 

- 

CD 

= 

CZ2 

ctf 

T 

" 

CD 

CD 

ou 

ho 

_ 

- 

*H 

w 

= 

P4 

+3 

r^ 

0) 

d 

cd 

C/l 

o 

- 
eft 

eS 

O 

-i 

rt 

o 

0 

Sao 

s 

= 

s- 

«rt 

cr! 

h 

|Jh 

'— 

J- 

: 

> 

CD 

<1 

— 
- 

CD 

£, 

- 

H  U 

fe 


no 


The  Modern  Gas  Tractor 


and  has  a  pulley  for  driving  stationary  machines.  A 
drawbar  is  provided  for  pulling  ploughs  and  other  ma- 
chines requiring  draft.  The  weight  of  this  truck  is  car- 
ried on  four  wheels,  therefore  when  used  for  ploughing 
ballast  must  be  put  over  the  driving  wheels  in  order  to 
provide  proper  traction.  As  the  machine  is  spring 
mounted  and  adapted  to  speeds  from  two  to  fifteen  miles 


_$  MOTOR 

*i/  COMBINED  TRACTION 

AND  STEERING  'wMEtL 

BELT  &ULLEY 


Fig.  19. — An  English  Tractor  With  Three  Bottom  Gang  Plough. 
This  Machine  Driven  by  Two  Cylinder  Vertical  Motor 
Utilizes  Front  Wheels  for  Steering  aud  Traction  Duty 
as  Well. 

per  hour  it  can  be  used  for  a  wide  variety  of  work.  In- 
stead of  using  rubber  tires  as  the  ordinary  motor  truck 
does,  the  wheels  are  provided  with  wooden  plugs  to 
adapt  the  tractor  to  hard  roads.  Traction  on  soft  ground 
is  provided  by  an  extension  rim  with  a  number  of  mud 
lugs  attached,  which  is  so  fastened  to  the  wheel  that 
these  automatically  grip  the  soil  when  the  wheels  sink 
to  a  certain  depth.     It  is  also  possible  to  move  a  hand 


The  Modern  Gas  Tractor  91 

lever  on  each  driving  wheel  which  causes  a  series  of  sharp 
spikes  to  project  beyond  the  periphery  of  the  wheel  to 
increase  traction  when  desired. 

A  machine  of  this  nature  is  shown  at  Fig.  18  which 
clearly  outlines  the  general  construction.  As  will  be  seen 
in  general  form  it  does  not  differ  radically  from  the  usual 
type  of  motor  truck.  As  it  is  provided  with  a  wagon  bed 
it  will  haul  grain,  hay,  stock,  coal,  lumber,  milk,  fruit, 
vegetables  and  other  kind  of  merchandise.  It  has  suffi- 
cient tractive  power  to  pull  three  14-inch  ploughs  and  a 
harrow  in  ordinary  stubble  ploughing  and  will  plough  an 
acre  an  hour.  It  will  pull  two  disks,  two  spike  harrows, 
two  seeders,  two  binders,  corn  planters,  a  road  grader, 
a  train  of  loaded  wagons,  or  any  other  machinery.  It  has 
a  draft  equal  to  ten  horses.  This  general  purpose  ma- 
chine, therefore,  is  ideal  for  the  small  or  medium  sized 
farm  as  it  will  not  only  haul  loads  of  all  kinds  on  its  own 
both'  but  will  do  field  work  and  serve  as  a  portable  belt- 
power  plant  when  desired. 

Many  other  special  tractor  forms  have  been  evolved, 
ranging  from  crudely  fashioned  home-made  contrivances 
to  highly  specialized  types  adapted  to  do  only  certain 
kinds  of  work.  Obviously  the  general  purpose  tractor 
must  suffer  if  compared  to  one  designed  to  do  a  specific 
kind  of  work,  but  its  wide  adaptability  gives  it  an  advan- 
tage over  the  specialized  forms  that  more  than  compen- 
sates for  its  lack  of  capacity  in  any  specific  work. 


CHAPTER  III. 

DESIGN  AND  CONSTRUCTION  OF  GAS  TRACTOR  POWER 
PLANTS. 

Power  Rating  Basis — Indicated,  Brake  and  Drawbar  Horse- 
power— Types  of  Gas  Engines — Comparing  Two  and  Four 
Stroke  Cycle  Power  Plants — Operating  Principles  of  Four- 
Cycle  Engine — How  Two-Cycle  Engine  Works — Advantages 
of  One  Cylinder  Motors — Features  of  Multiple  Cylinder 
Motors — Heavy  Duty  and  Medium  Duty  Engines — One 
Cylinder  Tractor  Engines — Two  Cylinder  Engines — Three 
Cylinder  Power  Plants — Tractor  Motors  with  Four  Cyl- 
inders. 

Power  Rating  Basis. — In  referring  to  the  power  of 
the  various  internal  combustion  engines  used  as  prime 
movers,  a  number  of  terms  are  employed  in  dealing  with 
the  subject  that  may  prove  confusing  to  the  layman. 
Therefore,  before  going  into  the  theory  of  engine  opera- 
tion to  any  extent  it  will  be  well  to  define  the  various 
methods  of  rating.  Many  believe  that  there  is  a  differ- 
ence between  a  gasoline  or  electrical  horse-power,  that 
produced  by  a  steam  engine  or  from  the  animal  itself. 
The  unit  of  work  remains  the  same  regardless  of  the 
source  of  energy  and  whether  the  power  is  produced  by 
steam,  gas,  electricity,  wind,  water  or  horses.  Various 
equivalents  for  a  horse-power  are  used,  for  example  an 
electrical  horse-power  is  746  watts.  There  are  actually 
four  common  methods  of  horse-power  rating  in  use,  each 
of  which  carries  an  intelligent  idea  of  its  meaning. 

Indicated,  Brake  and  Drawbar  Horse=power. — 
Indicated  horse-power  is  the  amount  of  energy  devel- 
oped   within    the   cylinders  of  any  heat  engine.     It  is 

92 


The  Modern  (i.vs  Tractor 


93 


determined  by  an  instrument  called  the  indicator,  which 
gives  a  card  or  graphic  chart  showing  the  pressure  in 
pounds  per  square  inch  exerted  upon  the  piston  of  the 
engine.  This  is  most  commonly  used  in  steam-engine 
practice  and  is  a  unit  of  interest  mainly  to  the  engineer 
or  designer  because  it  does  not  give  the  actual  power 
developed  by  the  motor.  There  are  mechanical  losses 
that  must  be  considered  before  the  actual  power  output 
of  the  power  plant  can  be  ascertained. 


Fig.  20. — Simple   Diagram   to   Show    One    Method   of   Making 
a  Brake  Test  of  Small  Engine. 

Brake  horse-powrer  represents  the  indicated  horse- 
power, less  the  losses  in  friction  of  the  working  parts  of 
the  motor  itself.  It  is  the  power  actually  delivered  to 
the  crankshaft  or  belt  pulleys  of  the  motor.  The  brake 
horse-power  is  easily  determined  by  any  form  of  absorp- 
tion dynamometer  of  which  the  Prony  brake  is  the 
simplest  form.  The  application  and  use  of  this  form 
of  power  indicator  can  be  clearly  understood  by  refer- 
ring to  Fig.  20  and  from  table  given  in  Appendix. 
Any  one  can  make  the  simple  testing  device  illustrated, 
without  any  other  instructions  than  given  in  the  cuts. 
Good   stout   4  X4-inch    lumber,    free    from    knots;     two 


!>4  The  Modern  Gas  Tractor 

blocks  curved  to  conform  to  the  periphery  of  the  belt 
pulley;  two  bolts  as  indicated  and  an  ordinary  platform 
scale  are  all  that  is  needed.  The  length  of  the  horizontal 
brake  beam  represented  by  the  letter  B  is  not  arbitrary, 
it  being  necessary  only  to  make  sure  that  this  should  be 
short  enough  and  have  sufficient  strength  to  prevent 
breaking  when  under  test. 

When  making  a  test,  the  first  thing  to  do  is  to  have 
the  engine  running  at  its  normal  speed  and  under  proper 
conditions  to  get  steady  power.  The  brake  blocks  do 
not  bear  against  the  belt  pulley  with  any  force  except 
that  produced  by  their  weight.  The  nut  on  one  of  the 
bolts  is  then  tightened  to  bring  the  brake  blocks  in  forci- 
ble contact  with  the  pulley.  This  tends  to  depress  the 
end  of  the  brake  beam  resting  on  the  load  transfer  mem- 
ber, which  is  supported  by  the  platform  of  the  weighing 
apparatus.  The  brake  beam  should  always  point  in  the 
direction  toward  which  the  fly-wheel  is  turning. 

The  rule  for  obtaining  the  power  delivered  by  the 
motor  is  a  simple  one.  Multiply  the  speed  at  which  the 
engine  pulley  is  turning  by  the  number  of  feet  in  the 
circumference  of  a  circle  having  a  diameter  twice  that 
represented  by  the  radius  B  and  then  multiply  this  result 
by  the  net  pounds  lifted  on  the  scale  when  the  two  nuts 
on  the  top  end  of  the  bolts  have  been  screwed  down  suf- 
ficiently so  that  the  brake  blocks  are  bearing  on  the 
engine  pulley  as  hard  as  possible  without  reducing  the 
motor  speed.  Divide  this  result  by  33,000  and  the 
quotient  will  equal  the  actual  power  of  the  engine. 

As  an  example,  consider  that  the  distance  B  between 
the  center  of  the  brake  pulley  and  the  portion  of  the 
beam  resting  on  the  scale  is  4  feet.  The  circufnference 
of  a  circle  of  this  radius  would  be  2X4X3.1416  which 
equals  25.1328  feet.    If  the  engine  pulley  is  running  200 


The  Modern  Gas  Tractor 


95 


revolutions  per  minute  and  the  lift  on  the  scales  is  100 
pounds,  we  have  the  following  expression: 

25. 13  x  200  x  100 


33,000 


=  15.23  horse-power. 


Fig.  21. — Making  a  Brake  Test  in  the  Field. 

At  Fig.  21  the  method  of  making  a  brake  test  of  a  tractor 
power  plant  in  the  field  is  clearly  indicated. 

Drawbar  horse-power  is  the  amount  of  power  actually 
exerted  in  doing  useful  work,  such  as  in  hauling.  We 
have  seen  that  the  difference  between  indicated  horse- 
power and  brake  horse -power  represented  the  amount 
of  power  lost  by  friction  in  the  engine.  If  we  deduct  the 
power  lost  by  friction  in  the  power  transmission  mechan- 
ism, owing  to  transmitting  it  through  bearings  and  gears, 
and  the  power  necessary  in  propelling  the  tractor  itself 
over  the  ground  from  the  brake  horse-power  at  the 
pulley,  we  obtain  the  drawbar  horse-power. 

This  cannot  be  determined  as  accurately  and  as  easily 
as  brake  horse-power  because  it  depends  to  a  consider- 
able degree  upon  the  condition  of  the  ground  and  the 


96 


The  Modern  Gas  Tractor 


adhesion  between  the  driving  wheels  of  the  tractor  and 
the  surface  over  which  they  are  moving.  Under  favor- 
able conditions  where  the  slip  is  very  slight,  the  draw- 
bar horse-power  of  a  well-designed  gas  tractor  would 
be  about  2/i  of  the  actual  brake  horse-power.  It  will 
not  be  as  high  as  this  unless  the  power-transmission 
mechanism  is  very  efficient  and  the  weight  distribution, 
wheel  and  gear  construction  is  such  as  to  get  the  most 
perfect  tractive  effort. 


Gauge 


Fig.  22. — The  Kennerson  Traction  Dynamometer,  an  Efficient 
and  Simple  Instrument  for  Measuring  Draf*:. 

The  drawbar  pull  of  a  tractor  is  determined  by  means 
of  some  form  of  traction  dynamometer,  such  as  shown 
at  Fig.  22.  This  instrument  is  placed  between  the 
source  of  power  or  drawbar  of  the  tractor  and  some 
immovable  body,  such  as  a  large  tree.  The  tractor  is 
started  and  the  maximum  amount  of  pull  is  indicated 
in  pounds  upon  the  gage  just  before  the  tractor-wheels 


The  Modern  Gas  Tractor  !»7 

slip  or  the  engine  stops.  This  dynamometer  may  also 
be  used  to  indicate  the  tension  in  tow  line  or  draft  gear. 
As  will  be  apparent,  an  instrument  of  this  nature  may  be 
used  very  easily  in  making  comparative  tests  between 
the  tractive  power  or  drawbar  pull  of  various  forms  of 
engine  and  will  also  indicate  the  amount  of  draft  needed 
to  haul  a  wagon,  pull  a  plough  or  do  any  other  work. 

The  most  easily  understood  rating,  and  one  generally 
used  in  describing  a  tractor  to  the  average  farmer  is  the 
horse  equivalent  horse-power.  This  enables  one  who 
wishes  to  know  how  the  work  of  a  tractor  will  compare 
with  the  actual  work  of  farm  horses  to  make  an  intelli- 
gent approximation.  It  is  difficult  to  make  exact  com- 
parisons inasmuch  as  no  two  horses  can  do  exactly  the 
same  amount  of  work,  and  furthermore  the  average 
animal  is  more  flexible  in  its  exertions  than  any  mechni- 
cal  tractor.  We  have  seen  that  the  horse  is  able  to  exert 
two  or  three  times  its  average  power  for  a  short  distance 
in  the  field,  while  a  tractor  has  no  such  great  overload 
capacity. 

The  horse  equivalent  power  of  a  tractor  is  consider- 
ably less  than  its  drawbar  horse-power  and  represents 
the  number  of  actual  average  farm  horses  that  a  tractor 
can  replace  in  every-day  work.  It  may  be  approximated 
by  dividing  the  drawbar  pull,  exerted  by  a  tractor  travel- 
ling at  two  miles  an  hour  by  200.  If  the  tractor  shows 
a  drawbar  pull  of  2,000  pounds  at  that  speed  its  drawbar 
horse-power  or  horse  equivalent  power  will  be  equal  to 
that  produced  by  ten  animals  of  average  size. 

Types  of  Gas  Engines. — Two  types  of  gas  engines 
have  been  applied  generally  to  furnish  power  for  trans- 
portation purposes.  These  differ  in  construction  and 
operating  cycle  to  some  extent,  though  in  all  forms  power 
is  obtained  by  the  direct  combustion  of  fuel  in  the  cylin- 


us 


The  Modern  Gas  Tractor 


ders  of  the  engine.  In  all  standard  engines  a  member 
known  as  the  piston  travels  back  and  forth  in  the  cylinder 
with  what  is  known  as  a  reciprocating  motion,  and  this 
in  turn  is  changed  into  a  rotary  motion  by  suitable 
mechanical  means  to  be  described  fully  in  proper  se- 


To  Tank 


-Inlet  Port 


Piston  Pin 
^Bronze  Bushing 
'Piston  Rings 
Crank  Case 


-Crank  Shaft 
-Crank  Pin 


Drain  Cock 


Fig.  23.— Sectional  View  of  Ellis  Three-Port,  Two-Cycle  Engine, 
Showing  All  Important  Parts. 


The  Modern  Gas  Tractor  99 

quence.  Gas  engines  may  operate  on  either  the  two- 
cycle  or  four-cycle  principle,  the  former  being  the  sim- 
plest in  action,  though  the  latter  is  easiest  to  under- 
stand. 

Comparing  Two  and  Four=stroke  Power  Plants. — 
The  sectional  view  of  a  two-cycle  engine  depicted  at 
Fig.  23  shows  the  three  moving  parts  employed.  The 
gas  is  introduced  into  the  cylinder  and  expelled  from  it 
through  ports  cored  into  the  cylinder  walls,  which  are 
covered  by  the  piston  at  a  certain  portion  of  its  travel 
and  uncovered  at  other  portions  of  the  stroke.  The  three 
moving  parts  are  the  piston,  connecting  rod  and  crank- 
shaft. If  this  type  of  power  plant  is  compared  with  the 
four-cycle  engine  shown  at  Fig.  24  it  will  be  apparent 
that  it  is  much  simpler  in  construction. 

In  the  four-cycle  engine  the  gas  is  admitted  into  the 
cylinder,  through  a  port  at  the  head  closed  by  a  valve, 
while  the  exhaust  gas  is  expelled  through  another  port 
controlled  in  a  similar  manner.  These  valves  must  be 
operated  by  mechanism  distinct  from  the  piston.  In 
addition  to  the  three  main  moving  parts  used  in  the 
two-cycle  engine  there  are  a  number  of  auxiliary  moving 
members  that  are  part  of  the  valve-operating  mechan- 
ism. The  four-cycle  engine  is  more  widely  used  because 
it  is  the  most  efficient  type.  The  two-cycle  engine  is 
simpler  to  operate  and  very  smooth  running  but  it  is  not 
as  economical  as  the  four-cycle  because  a  portion  of  the 
fresh  gas  taken  into  the  cylinder  is  expelled  through  the 
open  exhaust  port  with  the  burnt  gases  before  it  has  a 
chance  to  ignite.  As  a  four-cycle  engine  is  more  gener- 
ally used  its  method  of  operation  will  be  described  first. 

Operating  Principles  of  Four=cycle  Engines. — 
The  action  of  the  four-cycle  type  will  be  easily  under- 
stood if  one  refers  to  the  illustrations  at  Figs.  25  and  26. 


The  Modern  Gas  Tractor 


The  Modern-  Gas  Tractor  101 

It  is  called  a  four-stroke  engine  because  the  piston  must 
make  four  strokes  in  the  cylinder  for  each  explosion  or 
power  impulse  obtained.  The  principle  of  a  gas  engine  is 
similar  to  that  of  a  gun,  i.  e.;  power  is  obtained  by  a 
rapid  combustion  of  some  explosive  or  other  quick- 
burning  substance.  The  bullet  is  driven  out  of  a  gun 
barrel  by  the  powerful  gases  liberated  when  the  charge 
of  powder  is  ignited.  The  piston  of  a  gas  engine  is  driven 
toward  the  open  end  of  a  cylinder  by  the  expansion  of 
gases  resulting  from  combustion. 

The  first  operation  in  firing  a  gun  or  securing  an  ex- 
plosion in  the  cylinder  of  a  gas  engine  is  to  fill  the  com- 
bustion space  with  combustible  material.  The  second 
operation  is  to  compress  this  and  after  compression,  if 
the  charge  is  ignited,  the  third  operation  of  the  cycle 
will  be  performed.  In  the  case  of  the  gun  the  bullet  will 
be  driven  out  of  the  barrel,  while  the  piston  of  the  gas 
engine  will  be  forced  toward  the  open  end  of  the  cylinder. 
As  the  bullet  leaves  the  mouth  of  the  gun  the  barrel  is 
automatically  cleared  of  the  burnt  powder  gases  which 
escaped  to  the  outer  air  because  of  their  pressure.  The 
gun  must  be  thoroughly  cleared  before  the  introduction 
of  a  new  charge  of  powder.  In  a  gas  engine  the  fourth 
operation  or  exhaust  stroke  is  performed  by  the  return 
stroke  of  the  piston. 

The  parts  of  a  simple  engine  have  been  previously 
indicated,  and  in  order  to  better  understand  the  action 
it  will  be  well  to  consider  briefly  the  various  parts  and 
their  functions  The  cyl'nder  is  an  important  member 
because  it  is  in  this  portion  that  practically  all  the  work 
is  accomplished.  The  cylinder  is  provided  with  three 
ports,  one  through  which  the  gas  is  admitted,  controlled 
by  an  inlet  valve,  another  through  which  the  burnt  gas 
is  expelled,  closed  by  the  exhaust  valve,  and  the  third  in 


102 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  103 

which  the  spark  plug  used  to  ignite  the  compressed  gas 
is  screwed.  The  reciprocating  motion  of  the  piston, 
which  is  the  member  moving  up  and  down  in  the  cylin- 
der, is  transformed  into  a  rotary  motion  of  the  crank 
shaft  by  means  of  a  connecting  rod  and  crank  pin. 

In  the  simple  engine  shown  at  Figs  25  and  26  the  inlet 
valve  is  an  automatic  one,  while  the  exhaust  member  is 
raised  from  its  seat  by  a  mechanism  including  the  cam- 
shaft, cam,  valve-operating  bell  crank  and  plunger.  At 
Fig.  25-A  the  piston  is  starting  to  go  down  on  the  first 
stroke  of  the  four  necessary  to  produce  a  complete  cycle 
of  operations.  As  the  piston  descends  it  creates  a  suc- 
tion in  the  combustion  chamber,  the  automatic  valve  is 
drawn  down  from  its  seat  and  a  resh  charge  of  gas  is 
drawn  into  the  cylinder  through  the  inlet  pipe  which 
communicates  with  the  gas-supply  device  or  carburetor. 
The  inlet  valve  will  remain  open  until  the  piston  reaches 
the  bottom  of  its  stroke.  As  soon  as  the  pressure  inside 
the  cylinder  is  equal  to  that  outside  which  condition 
obtains  as  soon  as  the  piston  has  reached  the  end  of  its 
downward  stroke  and  the  cylinder  is  filled  with  gas  the 
inlet  valve  is  closed  and  the  piston  starts  to  return  on 
the  next  stroke  as  shown  at  Fig.  25-B. 

As  both  valves  are  closed  the  combustible  vapor  with 
which  the  cylinder  is  filled  is  compressed  into  a  much 
smaller  volume.  The  reason  for  compression  is  that  any 
agent  which  gives  out  energy  through  the  expansion  of 
gases  is  rendered  more  efficient  by  confining  it  in  a  re- 
stricted space  and  directing  the  whole  energy  against 
some  one  spot.  A  tuft  of  gun  cotton  could  be  ignited 
while  lying  loosely  in  the  hand  and  it  would  burn  freely 
but  without  explosion.  If  it  is  confined  in  a  gun  barrel 
and  exploded  it  will  drive  the  bullet  out  with  a  great 
amount  of  force  or  burst  the  metal  walls  of  the  con- 


104 


The  Modern  Gas  Tkactou 


Uj 


o 


The  Modern  (Ias  Tractor  10.~» 

tainer.  Gasoline  vapor  and  air  will  ignite  and  burn 
freely  at  atmospheric  pressure  and  a  gasoline  engine 
could  be  made  to  run  without  compression.  The  expan- 
sion of  the  unconfined  gases  would  not  be  great  enough 
to  do  effective  work,  however,  and  the  fullest  efficiency 
of  the  fuel  is  obtained  by  compacting  it  into  the  smallest 
possible  space  and  then  igniting  it  at  the  instant  when 
it  is  compressed  the  most. 

Any  chemical  action  requires  close  contact  between 
the  materials  producing  it,  if  it  is  to  occur  under  the  most 
favorable  conditions.  That  which  occurs  when  a  mixture 
of  gasoline  vapor  and  air  are  brought  into  contact  with 
the  flame  or  arc  of  the  electric  spark  is  practically  in- 
stantaneous if  the  gases  are  crowded  together.  If  the 
gas  is  not  properly  compressed,  the  action  becomes  more 
dilatory,  extending  to  a  slow  combustion  wherein  the 
temperature  is  not  raised  enough  to  expand  the  gases 
efficiently  as  the  degree  of  compression  is  lessened.  A 
good  example  of  slow  combustion  is  the  decay  of  wood, 
while  the  phenomenon  that  we  call  "burning"  may  be 
taken  as  an  illustration  of  quick  combustion.  It  is  said 
that  the  same  amount  of  heat  is  produced  by  either 
combustion  but  only  the  latter  produces  it  quickly 
enough  to  be  not'ceable. 

The  comparatively  slow  combustion  of  the  gases  in 
the  engine  cylinder,  when  at  atmospheric  pressure  would 
not  permit  the  energy  derived  from  the  heat  to  act  all  at 
once.  When  the  gases  are  compressed  the  particles  of 
vapor  are  in  such  intimate  contact  that  combustion  is 
practically  instantaneous  and  the  gases  give  off  maximum 
energy  by  expanding  their  utmost  due  to  the  high  tem- 
perature developed.  The  piston  is  also  in  a  position  to 
be  acted  upon  most  readily  as  the  force  due  to  pressure 
of  the  gas  is  directly  against  it  and  not  exerted  through 


10(5  The  Modern  <1ax  Tractor 

an  elastic  cushion  of  half-ignited  gas  as  would  be  the  case 
if  the  charge  was  not  compressed  before  ignition. 

When  the  piston  reaches  the  top  of  its  second  stroke 
the  compressed  gas  is  exploded  by  means  of  an  electric 
spark  between  the  points  of  the  spark  plug  and  the 
piston  is  driven  down  toward  the  open  end  of  the  cylin- 
der, as  indicated  at  Fig.  26-C.  At  the  end  of  this  down 
stroke  the  pressure  of  the  gases  is  reduced  to  such  a  point 
that  they  no  longer  have  any  value  in  producing  power. 
At  this  time  the  cam,  which  is  operated  in  timed  relation 
to  the  crank-shaft  travel,  raises  the  exhaust  valve  from 
its  seat  and  the  burnt  gases  are  expelled  through  the  open 
exhaust  port  until  the  cylinder  is  practically  cleared  of  the 
inert  products  of  combustion,  the  natural  scavenging  ac- 
tion being  assisted  by  an  upward  movement  of  the  piston. 
The  piston  once  more  begins  to  descend,  as  shown  at 
Fig.  25-A  and  the  inlet  valve  opens  to  admit  a  new 
charge.  The  rest  of  the  cycle  of  operations  follow  in  the 
order  indicated  and  are  repeated  as  long  as  the  cylinder 
is  supplied  with  gas  and  this  is  ignited. 

How  Two=cycle  Engines  Work. — The  two-cycle 
engine  works  on  a  different  principle,  as  while  only  the 
combustion  chamber  end  of  the  piston  is  employed  to 
do  useful  work  in  the  four-cycle  engine,  both  upper  and 
lower  ends  are  called  upon  to  perform  the  functions 
necessary  to  two-cycle  engine  operation.  Instead  of  the 
gas  being  admitted  into  the  cylinder,  as  is  the  case  with 
the  four-cycle  engine,  it  is  first  drawn  into  the  engine 
base,  where  it  receives  a  preliminary  compression,  prior 
to  its  transfer  to  the  working  end  of  the  cylinder. 

The  views  at  Fig.  27  show  clearly  the  operation  of  a 
two-port,  two-cycle  engine.  Assuming  that  a  charge  of 
gas  has  just  been  compressed  in  the  cylinder  and  that  the 
upward  movement  of  the  piston  while  compressing  the 


The  Modern  Gas  Tractor 


107 


o 


< 

be 


108  The  Modern.  Gas  Tractor 

gas  above  it  has  drawn  in  a  charge  through  the  auto- 
matic intake  valve  in  the  crank  case,  it  will  be  apparant 
that  as  soon  as  the  piston  reaches  the  top  of  its  stroke 
and  the  gas  has  been  properly  compressed  that  the  ex- 
plosion of  this  charge  by  an  electric  spark  will  produce 
power  in  just  the  same  manner  as  it  does  in  the  four- 
cycle motor.  As  the  piston  descends  due  to  the  impact 
of  the  expanding  gases,  it  closes  the  automatic  inlet 
valve  in  the  crank  case  and  compresses  the  gases  con- 
fined therein. 

When  the  piston  reaches  the  bottom  of  the  cylinder  it 
uncovers  the  exhaust  port  cored  in  the  cylinder  walls 
and  the  burnt  gases  leave  the  cylinder  because  of  their 
pressure.  A  little  further  downward  movement  of  the 
piston  uncovers  the  intake  port,  which  is  joined  to  the 
crank  case  by  a  by-pass  passage,  at  which  time  a  condi- 
tion exists  as  indicated  at  Fig.  27-B.  The  piston  has 
reached  the  bottom  of  its  stroke  and  both  exhaust  and 
inlet  ports  are  open.  The  burnt  gases  are  flowing  out 
of  the  cylinder  through  the  open  exhaust  port,  while  the 
fresh  gases  are  being  transferred  from  the  crank  case, 
where  they  had  been  confined  under  pressure  to  the 
cylinder.  The  fresh  gas  is  kept  from  passing  out  of  the 
open  exhaust  port  opposite  the  inlet  opening  by  a  deflec- 
tor plate  cast  on  the  piston  head,  which  directs  the  enter- 
ing stream  of  fresh  gas  to  the  top  of  the  cylinder. 

As  the  piston  goes  back  on  its  up  stroke  the  exhaust 
and  inlet  ports  are  closed  by  the  piston  wall  and  the 
charge  of  gas  is  compressed  prior  to  ignition.  As  the 
piston  travels  up  on  its  compression  stroke,  the  inlet 
valve  in  the  crank  case  opens,  due  to  the  suction  pro- 
duced by  the  piston  and  admits  a  charge  of  gas,  through 
the  open  crank  case  intake  port.  It  will  be  seen  that  an 
explosion  is  obtained  every  two  strokes  of  the  piston 


The  Modern  Gas  Tractor 


lid  The  Modern  Gas  Tractor 

instead  of  every  four  strokes,  as  is  the  case  with  a  four- 
cycle engine.  In  the  two-cycle  form  one  explosion  is 
obtained  for  each  revolution  of  the  crank  shaft,  while 
in  the  four-cycle  two  revolutions  of  the  crank  shaft  are 
necessary  to  obtain  one  power  impulse. 

The  operating  principle  of  the  three-port  two-cycle 
engine  outlined  at  Fig.  28  is  just  the  same  as  that  pre- 
viously described  except  that  the  gas  from  the  carburetor 
is  admitted  to  the  crank  chamber  through  a  small  port 
in  the  cylinder  wall,  which  is  open  when  the  piston 
reaches  the  top  of  the  stroke  as  shown  at  A.  The  three- 
port  method  of  construction  makes  it  possible  to  dis- 
pense with  the  automatic  inlet  valve  shown  in  Fig.  27, 
and  an  engine  of  this  kind  is  a  true  valveless  type. 

Advantages  of  One=cylinder  Motors. — As  the  first 
power  plants  developed  for  general  use  were  of  the  one- 
cylinder  pattern  and  this  type  motor  has  been  improved 
to  a  point  where  it  is  very  efficient  it  is  but  natural  that 
the  first  gas  tractors  would  utilize  the  perfected  one- 
cylinder  engine  then  so  widely  used  for  farm  power  in 
stationary  installations.  It  was  not  a  difficult  matter 
for  the  designer  of  the  early  gas  tractor  to  take  a  running 
gear  and  driving  mechanism,  similar  to  that  employed 
in  steam  tractors  and  to  replace  the  boiler  and  steam 
engine  with  a  horizontal  single-cylinder  stationary  form 
of  power  plant.  A  typical  one-cylinder  motor  of  the 
horizontal  type  such  as  used  on  the  lighter  I.  H.  C.  gas 
tractors  is  shown  at  Fig.  29. 

The  single-cylinder  engine  offers  a  main  advantage 
of  extreme  simplicity.  This  is  of  considerable  import- 
ance in  the  lighter  all-purpose  tractors  that  are  to  be 
operated  by  inexperienced  help.  Among  some  of  the 
disadvantages  that  may  be  cited  against  the  single- 
cylinder  power  plant  are  great  weight  in  proportion  to 


The  Modern  Gas  Tractor 


111 


power  developed,  lack  of  even  power  application  because 
only  one  stroke  out  of  four  made  by  the  piston  is  effec- 
tive. A  one-cylinder  engine  lacks  the  even  turning 
movement  and  steady  running  qualities  that  a  multiple 
cylinder  power  plant  possesses.     If  run  faster  or  slower 


Fig.  29. — Single  Cylinder  Power  Plant  Used  on  T.  H.  C.  Two 
Speed  Light  Tractor. 

than  the  critical  speed  for  which  it  is  designed  there 
will  be  considerable  vibration.  Despite  these  faults, 
the  single-cylinder  engine  is  very  practical  in  applica- 
tions to  light,  slow-speed  tractors. 

Features  of  Multiple  Cylinder  Motors. — Power  is 
obtained  in  the  multiple  cylinder  motor  by  using  a  num- 
ber of  cylinders  instead  of  one  large  member.  The 
cylinders  are  arranged  in  such  a  way  that  any  multiple- 
cylinder  motor  may  be  considered  as  a  number  of  single- 
cylinder  engines  joined  together  so  that  one  cylinder 
starts  to   deliver   power  to   the   crankshaft   where   the 


112  Tub  Modern  Gas  Tractor 

other  leaves  off.  By  using  a  number  of  smaller  cylinders 
instead  of  a  large  one  all  of  the  revolving  parts  may  be 
made  lighter  and  the  reciprocating  members  are  easier 
to  balance  because  the  weight  of  the  parts  in  one  cylinder 
often  counter-balances  the  reciprocating  mass  in  the 
other  that  works  in  connection  with  it. 


THIS  DIAGRAM   REPRESENTS   ONE     CYCLE     IN  WHICH  THE    PISTON   TRAVELS    20  INCHES 
i  REPRESENTS  POWER  i  '  REPRESENTS   NO  POWER 


Fig.  30. — Diagram  Showing  Advantages  of  Multiple  Cylinder 
Motors  and  Why  They  Deliver  Power  More  Evenly  Than 
Single  Cylinder  Types. 

Multiple-cylinder  engines  may  be  run  faster  than 
single-cylinder  ones  of  the  same  power,  are  not  so  heavy 
in  proportion  to  the  power  developed  and  produce  a 
more  even  turning  effect  at  the  crankshaft.  No  matter 
how  well  designed  the  single-cylinder  power  plant  is,  the 
power  impulses  will  come  in  jerks,  and  a  very  heavy  fly- 
wheel member,  or  pair  of  fly-wheel  members  is  needed  to 
equalize  the  intermittent  power  strokes.  In  a  multiple- 
cylinder  engine  where  the  explosions  follow  each  other 
in  rapid  succession  the  power  application  is  obviously 
much  more  even.  A  single-cylinder  engine  will  give  but 
one  useful  power  stroke  when  of  the  four-cycle  type,  to 
every  two  revolutions  of  the  crankshaft.  A  two-cylinder 
motor  will  give  one  explosion  every  revolution,  while  a 
three-cylinder  power  plant  will  give  three  explosions 
every  two  revolutions. 


The  Modern  Gas  Tractor  113 

The  real  value  of  a  multiple-cylinder  motor  is  more 
apparent  when  four  or  six  cylinders  are  used  because  in 
the  former  one  obtains  a  power  impulse  every  half  revo- 
lution of  the  fly-wheel,  while  in  the  latter  three-power 
strokes  are  delivered  every  revolution.  The  diagram 
presented  at  Fig.  30  compares  in  a  graphic  manner  the 
useful  power  impulse  of  engines  having  a  cycle  in  which 
the  piston  travels  twenty  inches.  The  shaded  parts 
represent  periods  where  power  application  obtains, 
while  the  unshaded  portions  represent  no  power.  In 
the  one-cylinder  engine  it  will  be  evident  that  less  than 
one-quarter  of  the  cycle  represents  useful  energy.  In 
the  two-cylinder  engine  the  explosions  are  evenly  spaced 
but  are  separated  by  appreciable  spaces  where  no  power 
is  developed. 

Eve,n  in  the  four-cylinder  engine  there  are  periods 
(corresponding  to  the  early  opening  of  the  exhaust  valves 
on  the  power  stroke)  where  no  useful  energy  is  directed 
against  the  crank  shaft.  The  torque,  or  power  applica- 
tion is  uniform  enough  for  all  practical  purposes,  except 
where  the  utmost  refinement  is  desired,  as  in  high-grade 
motor  car  power  plants.  In  the  six-cylinder  engine, 
however,  there  are  no  periods  in  the  cycle  of  operation 
where  the  crank  shaft  is  not  positively  driven.  In  fact, 
the  explosions  overlap  each  other  and  a  very  smooth- 
acting  power  plant  is  obtained.  For  tractor  service, 
however,  a  four-cylinder  motor  will  prove  to  be  very 
satisfactory  and  will  operate  with  minimum  vibration. 

Heavy  Duty  and  Medium  Duty  Engines. — It  is 
possible  to  divide  the  multiple-cylinder  motor  class  into 
two  general  groups.  One  will  include  all  engines  having 
horizontally  disposed  cylinders,  while  the  other  group 
will  be  composed  of  power  plants  having  vertical  cylin- 
ders.    The  horizontal  group  may  be  divided  into  sub- 


114  The  Modern  Gas  Tractor 

divisions,  where  some  of  the  motors  will  have  the  cylin- 
ders on  one  side  of  the  crank  shaft  and  the  other  where 
half  of  them  are  on  one  side  and  half  on  the  other  side  of 
crank-shaft  center.  The  form  in  which  the  two  cylinders 
are  placed  side  by  side  is  preferred  because  of  compact- 
ness, though  this  advantage  is  counteracted  by  difficul- 
ties which  obtain  in  proper  balancing.  Where  the  cylin- 
ders are  opposed  the  tendency  to  vibration  is  neutralized 
because  a  better  balance  of  reciprocating  parts  is  obtained 
and  the  explosions  follow  in  regular  sequence.  The 
vertical  motor  has  a  number  of  advantages  over  the 
horizontal  type.  There  is  less  liability  of  the  cylinder 
walls  wearing  out  of  round  and  it  is  easier  to  lubricate 
the  cylinder  when  the  head  is  at  the  top.  As  a  rule, 
multiple-cylinder  engines  of  the  vertical  type  are  much 
more  compact  and  easier  placed  on  the  tractor  frame 
than  horizontal  engines  of  the  same  power  and  number 
of  cylinders  would  be. 

Tractor  power  plants  are  often  referred  to  as  medium- 
duty  or  heavy-duty  engines.  The  heavy-duty  type  is 
one  where  all  the  bearings  and  working  parts  have  been 
proportioned  unusually  large.  It  is  believed  these 
engines  are  more  suitable  for  continuous  duty  at  full 
load  than  the  lighter  engines  where  the  bearings  are  not 
so  large.  This  is  apt  to  prove  confusing,  however, 
because  many  engines  considered  heavy-duty  power 
plants  must  be  built  very  heavy  to  withstand  the  vibra- 
tion and  stress  present  while  they  are  in  operation. 
Many  medium-duty  engines  would  be  capable  of  doing 
more  work  and  operate  for  a  longer  period  than  power 
plants  where  the  reciprocating  and.  rotating  members 
were  very  much  larger. 

•Reciprocating  parts  produce  strains  and  vibration  no 
matter  how  perfectly  an  engine  is  balanced    and   the 


The  Modern  Gas  Tractor  115 

extent  of  these  stresses  is  dependent  on  the  weight  of 
the  moving  parts  and  the  piston  velocity.  In  order  to 
prevent  undue  depreciation  heavy-duty  engines  which 
have  large  parts  must  operate  at  a  slower  speed  than  the 
medium-duty  power  plants  where  the  weight  of  the  re- 
ciprocating masses  is  less.  Heavy-duty  engines  are  usu- 
ally of  the  horizontal  type  and  have  one  or  two  cylin- 


Fig.  31.— Fly  Wheel  Side  of  Two  Cylinder  Horizontal  Motor 
Used  in  "Oil  Pull"  Tractors. 

ders,  while  the  medium-duty  types  are  almost  invari- 
ably of  the  four-cylinder  vertical  pattern. 

In  the  vertical  motor  of  the  four-cylinder  type  the 
parts  may  be  made  lighter  than  in  the  other  forms  and 
as  the  weight  of  the  piston  and  connecting  rod  is  entirely 
removed   from  the   walls   of  the   cylinder,   these  parts 


11  fi 


The  Modern  Gas  Tractor 


practically  float  in  a  film  of  oil  and  the  weight  is  carried 
in  such  a  way  that  the  least  wear  is  imposed  on  the 
cylinder  walls,  the  piston  and  piston  rings.  The  load 
is  carried  by  the  easily  adjusted  main  bearings  of  the 
engine  rather  than  the  cylinder,  which  can  be  restored 
to  true  bore  when  worn  only  at  considerable  expense. 


Fig.  32. — Double  Opposed  Motor  of  45  Horse-power  Used  on 
1.  H.  C.  Mogul  Tractor. 

The.  vertical  motor  construction  makes  it  possible  to  use 
a  very  efficient  lubricating  system  and  the  difficulty 
that  obtains  in  a  horizontal  engine  of  flooding  the  cylin- 
der head  with  oil  is  not  present  in  the  vertical  cylinder. 
The  oil  is  also  more  evenly  distributed  in  a  vertical 
motor  because  there  is  no  tendency  for  it  to  collect  at 


The  Modern  Gas  Tractor  117 

the  lowest  point,  which  is  the  wall  of  the  cylinder  directly 
under  the  piston  of  the  horizontal  engine. 

Another  advantage  of  the  vertical  cylinder  construc- 
tion is  that  the  vibratory  stresses  travel  in  vertical  lines 
and  are  resisted  by  parts  best  adapted  to  receive  them 
as  the  axles  and  wheels.  In  a  horizontal  motor,  vibra- 
tion must  be  absorbed  by  the  frame  and  gearing  and 
considerable  stress  is  placed  on  parts  not  well  adapted 
to  resist  them.  It  is  not  the  writers  intention  to  con- 
tend that  horizontal  motors  are  not  practical,  but  it  is 
evident  that  where  these  are  used  the  frame  parts  and 
gearing  must  be  heavier  because  they  are  called  upon  to 
take  vibratory  stresses  as  well  as  carry  the  weight  of  the 
engine.  As  a  rule  the  vertical  cylinder  motor  is  more 
accessible  than  the  horizontal  engine.  The  vital  parts 
which  need  more  or  less  attention,  such  as  the  valves, 
spark  plugs,  ignition  wiring,  water  piping,  etc.,  are  more 
easily  reached  than  in  the  horizontally  disposed  power 
plant.  Either  a  medium-duty  or  heavy-duty  engine  is 
suitable  for  tractor  propulsion,  though  the  preference  of 
most  designers  is  for  the  former  because  of  the  advan- 
tages previously  enumerated. 

One=cyIinder  Tractor  Engines. — The  construction 
of  a  typical  one-cylinder  tractor  power  plant  can  be 
easily  understood  by  referring  to  Fig.  29.  The  motor 
is  a  long-stroke,  heavy-duty  type  with  an  inclosed  crank 
case.  The  cylinder  is  supported  by  a  substantial  cast- 
iron  bed,  which  in  turn  is  attached  to  the  substantial 
I  beams,  forming  the  main  frame  members.  The  fly- 
wheels are  large  and  are  mounted  one  on  each  side  of 
the  crank  shaft.  The  heavy  fly-wheels  are  necessary  to 
equalize  the  intermittent  power  application  and  are 
arranged  in  the  manner  indicated  in  order  to  distribute 
the  twisting  strain  evenly  on  the  crank  shaft.     If  one 


118 


The  Modern  <tas  Tractor 


V- -  * 


6  S°§ 


The  Modern  Gas  Tractor  11!) 

large  wheel  was  carried  at  one  side  of  the  motor,  equal  in 
weight  to  the  two  fly-wheels,  then  the  crank  shaft  would 
have  to  be  strengthened  very  much  on  the  fly-wheel  side 
to  resist  the  twisting  strain  resulting  from  the  heavy 
rim  of  the  fly-wheel.  In  practically  all  stationary  and 
tractor  power  plants  of  the  single-cylinder  type  where 
the  fly-wheel  mass  is  great  it  is  common  practice  to 
mount  one  fly-wheel  at  each  side  of  the  motor  base. 
The  valves,  which  admit  the  gas  to  the  cylinder  and  pro- 
vide for  the  expulsion  of  the  burnt  products  of  combus- 
tion are  carried  in  a  detachable  cylinder  head  at  the  back 
end  of  the  motor.  In  this  construction  every  effort  has 
been  made  to  have  the  parts  accessible  and  the  engine 
shown  is  one  of  the  most  practical  single-cylinder  types 
which  has  demonstrated  its  worth  in  many  different 
applications. 

Two=cylinder  Tractor  Engine.— Two  forms  of 
double-cylinder  motors,  commonly  used  in  tractor  work 
are  shown  at  Figs.  31  and  32.  That  at  Fig.  31  is  a  form 
in  which  the  cylinders  are  horizontally  disposed  but 
mounted  side  by  side  at  one  side  of  crank-shaft  center. 
The  magneto,  oiler,  and  other  parts  are  placed  on  top  of 
the  engine  base,  where  they  will  be  easily  reached.  In 
motors  of  this  type  either  the  explosions  will  not  be 
separated  by  regular  intervals  or  the  mechanical  balance 
will  be  poor.  If  it  is  intended  to  have  the  weight  of  one 
piston  counter-balance  that  of  the  other,  and  crank  pins 
are  spaced  at  180  degrees  to  attain  this  end,  then  the 
explosions  will  follow  one  right  after  the  other,  which 
will  result  in  two  explosions  occurring  during  one  revolu- 
on  of  the  fly-wheel  and  no  explosion  during  the  other 
revolution.  Instead  of  being  separated  by  intervals 
of  180  degrees,  the  explosions  will  be  separated  by  inter- 
vals of  90  degrees  and  270  degrees  respectively.     At  the 


!L'0 


The  Modern  Gas  Tractor 


The  Modern  <1as  Tractor  121 

other  hand,  if  the  two  crank  pins  are  on  the  same  plane 
and  both  pistons  move  in  and  out  of  their  respective 
cylinders  together,  it  will  be  necessary  to  counter-bal- 
ance the  crank  shaft  just  as  though  the  engine  was  a 
single-cylinder  form.  The  explosions  will  be  evenly 
spaced,  however,  and  will  be  separated  by  an  interval  of 
180  degrees.  One  will  take  place  during  the  first  half  of 
the  first  revolution  of  the  fly-wheel,  while  the  other  will 
take  place  the  first  half  of  the  second  revolution. 

The  opposed  power  plant  shown  at  Fig.  32  is  a  form 
generally  favored  by  designers  when  two-cylinder  en- 
gines are  employed.  By  carrying  one  cylinder  at  each  side 
of  the  crank  shaft  center  it  is  possible  to  secure  a  better 
balance  of  the  reciprocating  parts  and  the  crank  shaft 
does  not  need  to  be  counter-balanced.  A  lighter  fly- 
wheel can  be  used  than  on  the  two-cylinder  unit  type 
and  the  explosions  are  evenly  spaced.  The  disadvantage 
of  this  form  of  motor  is  that  it  usually  is  long  and  occu- 
pies the  greater  part  of  the  available  space  on  the  tractor 
frame.  Both  of  the  two-cylinder  engines  shown  are 
practical  and  have  been  used  successfully. 

Three=cy Under  Power  Plants. — The  three-cylinder 
motor  is  a  type  that  is  very  seldom  used  because  most 
designers  prefer  stepping  directly  to  the  four-cylinder 
from  the  simpler  two-cylinder  types.  In  a  three-cylinder 
power  plant  the  crank  pins  are  arranged  on  thirds  of  the 
circle  or  120  degrees  apart.  Such  an  engine  is  usually 
very  satisfactory  in  action  as  regards  vibration  and 
evenness  of  torque.  The  reciprocating  members  are 
well  balanced  and  the  explosions  follow  in  regular 
sequence.  While  the  mechanical  balance  is  not  as  good 
as  that  obtaining  in  a  four-cylinder  power  plant  it  is 
much  superior  to  that  prevailing  in  two-cylinder  engines. 
The   regular   sequence   of   explosions   makes   it   deliver 


122 


The  Modern  Gas  Tractor 


power  more  uniformly  than  a  two-cylinder,  though  it 
does  not  deliver  as  steady  power  as  a  four-cylinder. 
A  typical  three-cylinder  tractor  power  plant  is  shown  in 
section  at  Fig.  33,  and  as  all  parts  are  clearly  indicated 
further  description  is  not  necessary.  Three-cylinder 
power  plants  have  not  received  the  wide  application  that 


Fig.  35.— The  Holt  Four  Cylinder  Power  Plant  With  Valves 
Opening  Directly  Into  the  Cylinder  Heads. 

the  four-cylinder  type  have  and  are  used  on  only  one 
prominent  make  of  tractor  to  the  writer's  knowledge. 

Four=cylinder  Motors. — The  four-cylinder  power 
plant  is  the  type  that  is  now  practically  universal  in 
motor-car  practice  for  all  light  and  medium  weight  cars. 
Many  of  the  tractors  now  on  the  market  are  equipped 
with    four-cylinder    power    plants    because    these    offer 


The  Modern  Gas  Tkactor 


123 


so 

3 


- 
3 

: 


124 


The  Modern  Gas  Tractor 


WATER  PI  PE 


MECHANICAL 
t\      OILER 


WATER 
PIPE 


GOVERNOR 
CASE 


EXHAUST 

INLET 
CARBURETOR 


MAGNETO 


Fig.  37. — Views  of  Well  Designed  Four  Cylinder  Power  Plant 
Used  in  "Twin  City"  Gas  Tractor.  Top  View  Shows 
Water  Manifolds  and  Mechanical  Oiler;  Bottom  View 
Presents  Valve  Side  and  Shows  Induction  and  Exhaust 
Manifolds,   Carburetor  and  Magneto. 


The  Modern  <1as  Tractor  125 

every  practical  advantage  that  is  needed,  and  more 
nearly  fill  the  requirements  of  the  ideal  tractor  power 
plant  than  do  the  simpler  one,  two  or  three-cylinder 
types. 

A  typical  cross  section  of  a  four-cylinder  engine  of 
the  automobile  type  which  has  been  applied  as  a  tractor 
power  plant  is  shown  at  Fig.  34.  It  will  be  evident  that 
the  four  cylinders  are  placed  tandem  on  a  common 
crank  case.  The  crank  shaft  has  four  throws,  one  for 
each  cylinder  and  three  main  bearings.  One  cf  the 
bearings  is  at  the  center  between  the  two  pairs  of 
cylinders,  the  other  two  bearings  are  at  the  front  and 
rear  end  respectively.  In  the  motor  shown  the  first  and 
fourth  pistons  travel  together  while  the  second  and 
third  pistons  move  at  the  same  time. 

The  compactness  of  this  type  of  power  plant  can  be 
well  understood.  As  will  be  seen  one  cam  shaft  serves 
to  operate  all  the  valves,  and  connections  are  easily  made 
for  the  inlet  and  exhaust  manifolds  and  water  piping. 
A  four-cylinder  vertical  engine  designed  especially  for 
tractor  use  is  shown  at  Fig.  35,  and  is  composed  of  four 
individual  cylinder  castings  of  the  valve-in-the-head 
type,  instead  of  the  two  twin  cylinder  castings  of  the 
valve  at  one  side  type  previously  illustrated. 

Two  other  practical  four-cylinder  traction  engines  are 
shown  at  Figs.  36  and  37.  In  the  latter  two  views  of 
the  motor  are  shown.  The  upper  view  clearly  shows  the 
method  of  installing  the  mechanical  oiler  on  the  crank 
case  near  the  fly-wheel  and  depicts  the  oil  leads  running 
to  the  various  cylinders  and  other  bearing  points. 
The  large  hand  holes,  which  give  access  to  the  crank 
case  interior  are  also  indicated  and  their  size  may  be 
judged  by  the  cover  plates,  which  serve  to  close  them. 


Ilm; 


Tin:  Modern  Gas  Tractor 


The  lower  view  is  the  valve  side  of  the  motor  and  shows 
clearly  the  governor  case,  the  method  of  installing  the 
magneto  and  carburetor,  the  design  and  method  of 
securing  inlet  and  exhaust  manifolds  and  the  location 
of  the  valves  in  pockets  at  the  side  of  the  L-shaped 
individual  cylinder  castings. 


Water  Jacket 

Inlet  Value 
Inlet  Value  Seat 
Inlet  Value  Chamber 

Water  Jacket 
Inlet  Value  Stem 
Wrist  Pin 
Piston 

Inlet  Value  Lifter  Rod 

Connecting  Rod 

Crank  Case 


Lifter 
Guide 


Fly  Wheel 

^Crank  Shaft  Bearing 
^Exhaust  Value  Cam 
Crank  Case 
-Exhaust  Cam  Shaft  Gear 
Exhaust  Cam  Shaft 


pIG  38.— Single  Cylinder  Four-Cycle  Motor  With  One  Half 
of  Cylinder  and  Crankease  Removed  to  Show  All  Im- 
portant Parts. 


CHAPTER  IV. 
GAS  TRACTOR  POWER  PLANT  COMPONENTS. 

Parts  of  Tractor  Engines  and  Their  Functions — Cylinder  Con- 
struction— The  Valve  System — Piston  and  Rings — Connect- 
ing Rod  Types — Crankshaft  Forms— Utility  of  Flywheel — 
Engine  Base  and  Bearings. 

Parts  of  Tractor  Engines  and  Their  Functions. — 

The  general  design  of  tractor  engines  having  been  con- 
sidered and  the  principles  upon  which  their  action  is 
based  outlined,  it  will  be  advisable  to  consider  more  in 
detail  the  various  parts  comprising  the  engine,  the  ma- 
terials of  which  they  are  made,  the  various  common 
forms  they  exist  in  and  their  functions.  In  the  cross- 
sectional  view  of  the  typical  four-cycle  engine  depicted 
at  Fig.  38  all  the  important  parts  of  a  single-cylinder 
power  plant  are  shown.  In  a  four-cylinder  engine  most 
of  these  parts  pertaining  to  the  cylinder  and  valve  opera- 
tion would  be  multiplied  by  four,  though  one  set  of  cam 
shafts  and  cam  shaft  gears,  one  engine  base  and  crank 
shaft  and  one  fly-wheel  would  be  all  that  would  be  needed 
whether  the  engine  has  one  or  six  cylinders.  The  parts 
of  a  multiple  cylinder  engine  are  thus  duplicates  of  each 
other  to  a  large  extent  and  when  the  parts  of  one  cylinder 
and  their  functions  are  understood,  it  will  not  be  difficult 
to  understand  any  four-cycle  gas  engine. 

The  cylinder,  which  is  a  "T"  head  form,  having  valves 
at  both  sides  is  attached  to  a  base  of  aluminum  in  which 
the  cam  shafts  and  crank  shaft  are  housed.     The  piston 

127 


128  The  Modern  Gas  Tractor 

is  the  reciprocating  member  that  moves  back  and  forth 
in  the  cylinder  and  it  is  joined  to  the  connecting  rod  by 
means  of  a  wrist  pin  passing  through  the  upper  end  of 
the  connecting  rod.  The  lower  portion  of  the  connecting 
rod  is  attached  to  the  crank  pin  of  the  crank  shaft.  As 
the  piston  travels  up  and  down  in  the  cylinder  it  turns 
the  crank  pin  just  the  same  way  as  the  reciprocating 
motion  of  a  sewing-machine  treadle  is  transformed  to  a 
turning  movement  of  the  large  driving  wheel.  The  cylin- 
der is  provided  with  a  water  jacket,  which  is  a  hollow 
space  cored  between  the  inner  and  outer  walls  through 
which  water  is  circulated  to  keep  the  engine  cool.  The 
valves  are  carried  in  side  pockets  extending  on  each  side 
of  the  cylinder  and  are  held  against  their  seats  by  means 
of  coil  springs. 

The  cam  shafts,  which  turn  the  cams  used  to  operate 
the  valves  are  driven  from  a  small  gear  on  the  crank 
shaft,  the  ratio  of  drive  being  two  turns  of  the  crank 
shaft  for  one  turn  of  the  cam  shaft.  In  all  four-cycle 
motors  of  conventional  design  regardless  of  the  number 
of  cylinders  used  the  cam  shafts  always  turn  at  one  half 
crank  shaft  speed.  The  valves  are  raised  from  their 
seats  by  means  of  push  rods,  which  transfer  the  motion 
imparted  by  the  cam  point  raising  the  roll  which  bears 
against  the  cam.  These  members  are  steadied  by  guide 
bushings  screwed  into  the  engine  crank  case. 

The  starting  crank  is  used  to  turn  the  crank  shaft 
through  the  preliminary  movements  necessary  for  the 
piston  to  draw  in  a  charge  of  explosive  gas  and  compress 
it.  When  the  gas  is  exploded  by  the  electric  spark  which 
occurs  between  the  points  of  the  spark  plug  mounted  in 
the  cylinder  head,  the  piston  is  driven  down  and  a  cer- 
tain amount  of  the  energy  produced  by  the  explosion  is 
stored  in  the  fly-wheel  rim.     As  a  general  rule,  after  the 


The  Modern  <1.\s  Tractor  129 

first  explosion,  the  engine  will  continue  to  run  without 
hand  cranking. 

The  inlet  valve  is  used  to  admit  the  fresh  gas  from  the 
carburetor  to  the  combustion  chamber  and  is  raised  from 
its  seat  when  the  piston  starts  to  go  down  on  the  induc- 
tion stroke.  It  remains  open  until  the  piston  has  reached 
the  bottom  of  this  stroke  and  the  cylinder  is  filled  with 
gas.  While  the  piston  has  been  going  down  the  cam 
shaft  has  been  turning  and  when  the  piston  reaches  the 
bottom  of  its  stroke  the  cam  point  has  revolved  until  it 
is  out  of  contact  with  the  roller  in  the  valve  plunger  and 
the  valve  spring,  which  is  not  indicated  but  similar  to 
that  shown  on  the  exhaust  valve,  returns  the  inlet  valve 
to  its  seat  in  the  valve  chamber. 

The  exhaust  valve  does  not  open  until  the  piston  has 
made  two  more  strokes,  one  the  compression  the  other 
the  expansion,  or  power  stroke.  When  the  piston  has 
covered  approximately  seven-eights  of  its  movement  on 
the  power  stroke  the  exhaust  cam  turns  around,  raises 
the  push  rod,  which  in  turn  raises  the  exhaust  valve  from 
its  seat,  and  permits  the  burnt  gases  to  escape  through 
the  open  exhaust  port.  The  valve  remains  open  during 
the  entire  upward  stroke  of  the  piston,  closing  when  the 
piston  reaches  the  top.  The  inlet  cam  has  now  come  into 
action  again  and  another  fresh  charge  of  gas  is  drawn 
into  the  cylinder  during  the  beginning  of  the  next  cycle 
of  operation.  From  the  foregoing  description  it  will  not 
be  difficult  to  understand  the  action  of  the  various  parts 
of  the  four-cycle  engine  and  the  relation  these  members 
bear  to  each  other. 

Cylinder  Construction. — The  cylinder  is  one  of  the 
most  important  parts  of  any  form  of  heat  engine  and  it 
is  subjected  to  greater  stress  than  any  other  member. 
As  a  rule  cylinders  are  made  of  cast  iron  and  unless  of 


130  The  Modern  Gas  Tractor 

the  air-cooled  form  have  water  jackets  cast  integral. 
Tractor  engines  of  the  usual  pattern  use  individual 
cylinder  castings,  though  some  of  the  forms  which  are 
built  according  to  automobile  practice  have  the  cylin- 
ders cast  in  pairs.  Tractor  engines  are  generally  of  large 
bore  and  long  stroke  because  power  is  obtained  by  large 
piston  displacement  rather  than  high  crank-shaft  speed. 


Fig.  39.— Cylinder  With  Both  Valves  on  One  Side,  Four  Ring 
Piston  and  Marine  Type  Connecting  Rod. 

The  conventional  form  of  gas-engine  cylinder  is  outlined 
at  Fig.  39  in  connection  with  the  piston  and  connecting 
rod.  This  cylinder  is  of  the  L  form  and  has  the  water 
jacket  cast  integral.  Both  valves  are  carried  at  one  side 
of  the  cylinder  head  which  is  a  unit  with  the  cylinder. 
A  cross-section  through  a  cylinder  of  this  form  is  shown 
at  Fig.  40.  The  large  water  spaces  surrounding  the 
cylinder  walls  and  combustion  chamber  are  clearly  indi- 
cated.   The  bore  of  the  cylinder  is  finished  very  smoothly 


Tin;  Modern  Gas  Tuactor 


131 


in  order  that  the  piston  may  slide  up  and  down  with 
minimum  friction.  Gas-engine  cylinder  castings  are 
commonly  given  a  preliminary  boring  cut  and  then  are 
set  away  to  age  or  season  for  a  number  of  weeks  before 
any  more  machine  work  is  done  on  the  casting.  Some- 
times cylinders  are  annealed  before  they  are  put  away  to 


Fig.  40. — Sectional  View  of  "L"  Head  Cylinder  Showing  Water 
Spaces  Around  Combustion  and  Valve  Chamber, 
j 
age.     The  removal  of  the  scale  from  the  interior  of  the 

cylinder  relieves  some  of  the  stresses  produced  in  the 
metal  when  the  cylinder  was  cast  and  the  seasoning- 
operation  permits  it  to  assume  a  definite  shape.  After 
aging  the  cylinders  may  be  finish-bored  and  the  walls 
smoothed  by  a  reaming  process  or  the  bore  is  finished  by 
grinding. 

Some  cylinders  have  the  valves  placed  so  they  open 
directly  into  the  cylinder  head,  as  shown  at  Fig.  41. 


132 


The  Modern   <tas  Tractor 


Relief  Exhaust 


Oil  Circulating 
Pump 


Fig.  41. — Sectional    View    of    Valve   in    Head    Vertical    Motor 
Used  on  Hart-Parr  Tractors,  Cylinder  and  Head  Integral. 


The  Modern  Gas  Tractor  133 

When  this  is  done  two  methods  of  cylinder  construction 
are  possible.  In  the  one  that  is  more  widely  used  the 
cylinder  head  is  a  separate  casting,  carrying  the  valves, 
and  is  bolted  to  the  cylinder  member  as  outlined  at 
Figs.  42  and  43.  The  cylinder  design  depicted  at  Fig. 
41  is  a  one-piece  member  having  inserted  valves,  these 
members  being  mounted  in  removable  cages. 

Owing  to  the  large  size  of  tractor  cylinders  they  are 
never  cast  in  blocks  of  four  as  very  often  obtains  in  the 
latest  automobiles.  The  individual  cylinder  casting  has 
much  in  its  favor,  when  made  in  large  sizes.  More  uni- 
form cooling  is  important  because  it  insures  that  the 
change  of  form  due  to  increase  of  temperature  will  be 
regular.  This  condition  is  more  easily  obtained  when 
the  individual  cylinder  is  used  than  when  block  castings 
are  employed.  If  one  of  the  cylinders  of  a  tractor  power 
plant  should  become  damaged  it  is  much  cheaper  to  re- 
place the  single  large  member  than  it  would  be  to  replace 
a  cylinder  block  of  two  or  four  cylinders. 

The  method  of  construction  outlined  at  Fig.  42  has  the 
advantage  that  the  cylinder  head  may  be  easily  removed 
whenever  it  is  desired  to  remove  accumulations  of  car- 
bon from  the  cylinder  interior  or  when  the  valves,  which 
seat  directly  into  the  cylinder  head  are  to  be  ground. 
Direct  gas  passages  are  possible  and  the  entering  fresh 
gas,  or  the  outgoing  exhaust  gas  meets  with  little  resist- 
ance, such  as  would  be  the  case  if  the  gas  stream  was 
forced  to  turn  many  corners.  A  typical  cylinder  head 
detached  from  the  cylinder  casting  is  shown  at  Fig.  43. 
It  will  be  noticed  that  very  large  valves  are  used  and  that 
these  seat  directly  into  the  cylinder  head  face.  A  tight 
joint  is  insured  between  the  head  and  the  cylinder  cast- 
ing by  the  use  of  a  heat-resisting  packing,  which  is  com- 
pressed tightly  between  the  two  members  by  six  sub- 


iu 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor 


135 


stantial  bolts.  The  rectangular  spaces  between  the 
bolt  holes  are  ports  to  permit  free  circulation  of  ccoling 
water  around  the  cylinder  head. 

Most  tractor  engines  are  of  the  long-stroke  type,  the 
ratio  of  the  stroke  to  the  bore  being  about  one  and  one- 
half  or  two  to  one.  A  long-stroke  motor  will  pull  much 
better  at  low  speed  than  a  short-stroke  type,  and  as  most 
tractor   engines   are    of    the   moderate   speed  form   the 


Fig.  43. — Exterior  Face  of  Detachable  Cylinder  Head  Shown 
at  A  Outlines  Valve  Retention  by  Cages.  Interior  Face 
Shown  at  B  Indicates  Large  Valves  Possible  by  This 
Construction. 

stroke  must  be  long  in  order  to  obtain  an  efficient  piston 
speed. 

Cylinders  are  usually  fastened  to  the  engine  base  by 
means  of  bolts  passing  through  a  substantial  flange  cast 
integral  with  the  lower  portion.  This  permits  of  ready 
removal  when  repairs  are  necessary  without  dismantling 
the  entire  engine.  In  some  motors  where  the  cylinder 
heads  are  detachable  it  is  possible  to  remove  the  piston 
and  connecting  rod  assembly  through  the  open  end  of 
the  cylinder  without  removing  that  member  from  the 


130  The  Modern  <1as  Tractor 

engine  base.  Sometimes  when  the  separable  head  con- 
struction is  employed  the  cylinder  and  part  of  the  engine 
base  are  cast  together,  though  this  is  not  considered 
good  practice  except  on  small  stationary  power  plants. 

The  Valve  System. — The  location  of  the  valves  and 
shape  of  the  combustion  chamber  are  factors  that  have 
a  material  bearing  upon  the  power  obtained  from  the 
gasoline  motor.  It  is  obvious  that  the  gases  must  be 
admitted  taand  discharged  from  the  cylinder  as  quickly  as 
possible  in  order  that  no  back  pressure  will  be  produced 
that  will  prevent  the  cylinder  filling  promptly  or  the 
burnt  gases  exhausting  rapidly.  Valve  sizes  also  have  a 
decided  bearing  upon  the  speed  and  power  of  the  motor 
and  some  valve  locations  permit  the  use  of  larger  mem- 
bers than  do  others  without  the  penalty  of  using  unsys- 
metrical  cylinder  castings.  There  are  many  ways  in 
which  valves  may  be  placed  in  the  cylinder  and  each 
system  has  some  advantages.  The  cylinder  shown  at 
Fig.  38  is  known  as  the  "T"  form  and  the  valves  are 
carried  at  opposite  sides  of  the  cylinders.  It  is  necessary 
to  provide  two  cam  shafts  for  valve  operation  with  this 
method  of  construction  and  theoretically  this  is  the 
worst  form  of  combustion  chamber  as  far  as  heat  effici- 
ency is  concerned.  The  cylinder  of  the  "L"  type,  such 
as  shown  at  Fig.  39  is  very  widely  used  because  both 
valves  may  be  actuated  from  a  common  cam  shaft.  The 
combustion  chamber  form  is  more  efficient  than  the  "T" 
head  construction,  though  it  is  possible  to  use  larger 
valves,  and  manifolds  with  the  latter,  than  with  the  "L" 
construction. 

The  method  of  valve  application  shown  at  Fig.  42  has 
many  advantages.  It  is  possible  to  waterjacket  the 
valves  thoroughly,  which  is  somewhat  difficult  to  do 
when  the  valves  are  mounted  in  cages.     As  the  cooling 


The  Modern  Gas  Tractor  137 

water  is  in  contact  with  the  walls  of  the  valve  chambers, 
there  is  no  loss  of  heat  conductivity,  as  there  would  be 
at  the  joint  of  the  inserted  cage  type.  The  valves  may 
be  large  and  as  there  are  no  pockets  it  is  possible  to  have 
a  combustion  chamber  of  the  most  efficient  form.  The 
cylinder  is  easily  cast  and  machined  and  as  the  interior 
face  of  the  cylinder  head  may  be  finished  smooth  the 
combustion  chamber  has  no  projecting  particles  which 
may  serve  as  anchoring  points  for  carbon  or  which  may 
cause  preignition  troubles  by  getting  red  hot. 

The  method  of  valve  operation  and  placing  has  much 
to  do  with  the  size  of  the  valve,  and  the  review  of  the 
various  methods  of  valve  installation  has  shown  that  the 
largest  size  valves  can  be  used  in  motors  of  valve-in-the- 
head  type.  If  valves  are  of  the  automatic  type,  i.  e.,  open 
by  the  suction  of  the  piston,  they  should  be  about  20 
per  cent,  larger  in  diameter  than  mechanically  operated 
valves.  The  valve  diameter  should  be  equal  to  half  of 
the  cylinder  bore  if  possible.  The  valves  with  the  larger 
area  do  not  have  to  lift  as  high  as  the  smaller  members 
and  they  are  quieter  in  action  besides  impeding  the  gas 
flow  less. 

There  are  two  common  methods  of  valve  construction, 
one  in  which  the  valve  head  is  made  of  cast  iron  and 
the  stem  of  machinery  steel  attached  to  the  head  by 
riveting,  the  other  where  the  valve  is  machined  from  a 
one-piece  forging  of  nickel  or  machinery  steel.  Bevel- 
seated  valves  are  generally  used  in  gasoline  engines  and 
most  of  these  are  provided  with  screw-driver  slots  on 
top  of  the  head  in  order  that  they  may  be  turned  on  their 
seat  when  grinding.  Sometimes  valves  are  made  by 
electrically  welding  a  nickel  steel  head  to  a  carbon  steel 
stem.     This  is  considered  a  better  method  of  construe- 


138 


The  Modern  Gas  Tractor 


Fig.  44. — Front  View  of  Power  Plant  With  Timing  Gear  Case 
Cover  Removed,  Showing  Conventional  Method  of  Driv- 
ing Cam  Shaft. 

tion  than  either  of  the  two  previously  mentioned  because 
there  is  no  possibility  of  the  valve  heads  becoming  loose 
on  the  stem  as  is  sometimes  the  case  when  a  cast-iron 
head  is  riveted  to  a  steel  stem.  It  is  preferable  to  the 
one-piece  nickel  steel  construction  because  this  material 
does  not  wear  as  well  as  does  ordinary  machinery  steel. 
The  factor  of  endurance  is  not  slighted  in  order  to  use 


The  Modern  Gas  Tractor  139 

the  metal  that  has  a  high  degree  of  resistance  to  heat. 
The  composite  valve  construction  has  the  advantage 
that  the  head  is  made  of  a  heat-resisting  material,  while 
the  stem  is  made  of  steel  that  will  not  wear  the  valve- 
stem  guide.  As  the  head  and  stem  are  fused  together  by 
an  electric  current  it  is  impossible  to  distinguish  the  joint 
and  though  made  of  different  materials  the  valve  is  prac- 
tically one  piece. 

Valves  are  operated  by  means  of  cams  which  may  raise 
the  valve  from  its  seat  through  the  medium  of  a  simple 
plunger,  as  in  the  "T"  and  "L"  head  motors  or  by  means 
of  rocker  arms  and  tappet  rods  used  with  valve-in-t  he- 
head  motors.  A  cam  is  a  small  metal  wheel  having  a 
raised  projection  at  one  point  of  the  circle.  This  raises 
the  valve  plunger  when  it  comes  in  contact  with  it. 
When  the  cam  point  is  not  in  contact  with  the  plunger 
there  is  a  clearance  between  the  plunger  roller  and  the 
cam  circle  and  the  valve  remains  seated  by  virtue  of 
spring  pressure. '  Cam  shafts  may  be  driven  from  the 
crank  shaft  by  any  form  of  positive  gearing.  Sometimes 
they  are  driven  by  means  of  silent  chains  and  sprocket, 
though  the  usual  method  of  drive  is  by  gears.  A  typical 
timing  gear  assembly  is  shown  at  Fig.  44.  In  this  the 
pinion  A  is  driven  by  a  gear  of  the  same  size  attached  to 
the  crank  shaft.  It  meshes  with  the  gear  B,  which  is 
twice  as  great  in  diameter,  which  turns  the  cam  shaft  at 
half  engine  speed.  The  small  gear  C  is  used  to  drive  the 
water-circulating  pump  and  mechanical  oiler.  Timing 
gears  of  the  better  class  tractor  engines  are  encased  in 
order  to  exclude  dirt  and  grit  and  retain  lubricant. 

Piston  and  Rings. — The  piston  is  a  cast-iron  recipro- 
cating member  that  fits  into  the  cylinder  and  which 
receives  the  impact  of  the  exploding  gas.  It  is  one  of 
the  simplest  elements  of  the  tractor  power  plant  and  is 


1411 


The  Modern  Gas  Tractor 


one  part  that  does  not  change  much  in  form  when  used 
in  different  motor  designs.  It  is  a  cylindrical  member 
which  has  bosses  in  its  interior  to  hold  the  wrist  pin  and 
grooves  cut  on  the  exterior  wall  in  which  cast  iron  pack- 
ing rings  are  placed.  Three  forms  of  pistons  are  shown 
at  Fig.  45.  That  at  A  is  used  in  two-cycle  motors  and 
has  a  deflector  plate  or  member  cast  integral  with  the 
head.    That  at  B  is  the  usual  form  used  in  the  medium 


Fig.  45. — Types  of  Pistons  Commonly  Used.  A — Piston  With 
Deflector  for  Two  Cycle  Engine.  B — Piston  With  Four 
Rings  and  Connecting  Rod  in  Place,  Used  on  Medium 
Duty   Engines.     C — Long   Piston  of  Heavy  Duty  Engine. 


duty  engines  and  is  shown  with  connecting  rod  in  place. 

That  at  C  is  a  long  piston,  such  as  used  in  a  heavy-duty 

engine.    A  piston  with  rings  removed  is  shown  at  Fig.  46. 

As  it  is  imperative  that  the  pistons  be  free  in  the 


The  Modern  (Jas  Tractor  141 

cylinders  they  are  usually  machined  several  thousandths 
of  an  inch  smaller  than  the  cylinder  bore  in  order  to 
leave  sufficient  clearance  between  the  piston  and  cylinder 
walls  for  a  film  of  oil  and  to  allow  for  expansion  due  to 
heat.  To  make  a  gas-tight  joint,  packing  rings  are  placed 
in  the  grooves  of  the  piston.  These  have  sufficient 
elasticity  so  that  they  bear  tightly  against  the  cylinder 
wall.    As  there  is  but  a  limited  amount  of  ring  surface  in 


Fig.  46. — Piston  With   Packing   Rings   Removed. 

contact  with  the  cylinder  and  the  split-piston  rings  are 
resilient  so  that  they  conform  to  irregularities  in  cylinder 
bore  there  is  but  little  friction  between  properly  fitted 
rings  and  the  cylinder  wall.  The  piston  is  free  to  move 
up  and  down  in  the  cylinder  and  still  a  gas-tight  joint  is 
obtained  by  the  use  of  the  rings. 

These  packing  members  are  made  in  two  forms,  the 
eccentric,  in  which  one  side  of  the  ring  is  thinner  than 
the  other,  and  the  concentric,  in  which  the  ring  is  a  uni- 
orm  thickness  at  all  points.  In  some  cases  the  piston- 
ring  grooves  are  provided  with  pins  to  keep  rings  from 
turning  around  on  the  piston  until  all  the  slots  are  in 
line.  The  common  form  of  joint  is  the  lap  or  step  joint, 
which  is  shown  in  the  piston  rings  depicted  at  B  and  C, 
Fig.  45. 

Connecting  Rod  Types. — The  form  of  the  con- 
necting rod  depends  upon  the  type  of  engine  in  which 
it  is  used.     As  a  general  rule  connecting  rods  are  more 


141' 


The  Modern  Gas  Tractor 


than  twice  as  long  as  the  stroke  of  the  piston.  They  are 
usually  made  of  steel  and  either  forged  or  formed  from  the 
slab.  Sometimes  they  are  made  of  high-tensile  strength 
bronze  castings.  It  is  desirable  to  have  softer  metals 
in  contact  with  the  crank  shaft  than  those  of  which  the 
connecting  rods  are  composed  so  bushings  of  phosphor 
bronze  or  babbit  metal   are  employed  at  the  ends  that 


Fig.  47. — Types  of  Connecting  Rods  Used  in  Tractor  Engines. 
A — Simple  Marine  Type  Used  in  Long  Stroke  Motor. 
B — Built-up  Marine  Type  With  Adjustable  Wrist  Pin  Box. 
C — Marine  Type  With  Wrist  Pin  Bushing  Adjustment 
By  Wedge.  D — Simple  Hinged  Lower  Cap  Type  Used 
in   Vertical   Cylinder   Short   Stroke  Motor. 

are  to  receive  the  crank  pin  and  wrist  pin.  Bronze  is 
commonly  used  at  the  upper  end  on  account  of  the  heat 
this  bearing  is  subjected  to,  while  the  white  metal  is 
used  at  the  lower  or  crank-pin  end. 

The  upper  end  of  the  connecting  rod  may  be  one 
piece  because  the  wrist  pin  can  be  introduced  after  con- 
necting rod  is  in  place  between  the  bosses  of  the  piston. 


The  Modern  Gas  Tractor  143 

Owing  to  the  irregular  shape  of  the  crank  shaft  it  is 
necessary  to  make  the  lower  end  of  the  connecting  rod 
in  two  pieces.  Various  designs  of  connecting  rods  are 
shown  at  Fig.  47.  That  at  A  is  a  simple  drop-forged  type 
used  in  long-stroke  engines,  the  connecting  rod  and  the 
upper  half  of  the  crank-pin  bearing  are  formed  integral 
while  the  lower  cap  is  the  separable  member  held  in  place 
by  bolts.  The  upper  end  is  provided  with  a  split  lug 
which  is  clamped  together  by  a  bolt  to  hold  the  wrist- 
pin  bushing  in  place.  The  form  outlined  at  B  is  a  marine- 
type  rod  composed  of  a  central  portion  of  steel  having 
"T"  pieces  formed  integral  at  each  end.  Both  wrist-pin 
bushing  and  crank-pin  bearing  are  made  in  two  pieces 
of  bronze  and  are  fastened  to  the  flange  ends  by  means  of 
steel-securing   bolts. 

The  connecting  rod  shown  at  C  is  somewhat  similar 
in  design  except  that  it  is  rectangular  in  section  instead 
of  round.  This  is  also  a  marine-type  connecting  rod 
having  bronze  boxes  at  the  upper  and  lower  end.  The 
wrist-pin  boxes  are  carried  in  the  upper  end  of  the  con- 
necting rod  which  forms  a  box  around  them  in  such  a 
way  that  they  may  be  tightened  to  compensate  for  wear 
by  means  of  a  wedge  and  adjusting  bolt.  The  member 
outlined  at  D  is  a  modified  marine  form  in  which  the 
lower  bearing  cap  is  a  hinged  member  retained  by  one 
bolt  instead  of  two  as  in  the  other  construction.  This 
form  of  connecting  rod  is  generally  used  on  medium-duty 
engines,  while  the  other  three  types  are  used  on  heavy- 
duty  power  plants.  The  various  structural  shapes  in 
which  the  main  portion  of  the  rod  can  be  formed  are  also 
clearly  shown  at  Fig.  47.  That  at  A  is  an  I-beam  section. 
At  B  the  section  is  circular.  The  connecting  rod  at  C 
has  an  approximately  rectangular  cross  section,  while 
that  at  D  is  an  H  section  rod. 


144 


The  Modern  Gas  Tractor 


Bearing  adjustment  is  obtained  in  all  cases  by  re- 
moving shims  from  between  the  halves  of  the  boxes  and 
screwing  them  closer  together  by  means  of  through 
bolts.  A  number  of  liners  are  used,  these  being  thin  brass 
or  copper  stock  several  thousandths  of  an  inch  thick. 
As  the  brasses  wear,  shims  may  be  removed  and  the 
boxes  brought  closer  together  to  take  up  any  lost  motion 
that  exists. 


H 

A 

jjtf 

m^^^^^^^^l 

w    B 

Fig.  48. — Types  of  Single  Cylinder  Crankshafts.  A — One 
Throw  Shaft  Without  Balance  Weights.  B— Crankshaft 
With   Counterbalance   to    Reduce   Vibration. 


Crank=shaft  Forms. —  As  practically  the  entire 
duty  of  transmitting  the  power  developed  by  the  motor 
devolves  upon  the  crank  shaft  these  must  be  made  of 
the  highest  quality  steel  and  possess  exceptional  strength. 
They  are  usually  made  of  drop  or  machine  forgings, 


The  Modern  Gas  Tractor  145 

though  sometimes  they  are  blocked  out  of  a  solid  slab  of 
metal.  The  form  of  the  shaft  depends  upon  the  number 
of  cylinders.  Those  shown  at  Fig.  48  are  for  single-cylin- 
der motors  as  they  have  but  a  single  crank  throw.  That 
at  A  is  a  simple  form  used  in  motors  where  the  counter- 
balance weights  are  attached  to  the  fly-wheels,  while 
that  at  B  has  the  weights  (which  are  intended  to  balance 
the  reciprocating  parts)   attached  to  the  crank  webs. 


Fig.  49. — Forging  For  Two  Throw  Crankshaft. 

The  forging  of  a  two-cylinder  crank  shaft  is  shown  at 
Fig.  49.  It  will  be  seen  that  in  this  member  the  cranks 
are  spaced  on  the  halves  of  the  circle  or  180  degrees 
apart.  Crank  shafts  used  with  single-cylinder  motors 
consist  of  two  webs,  one  crank  pin  and  the  crank  shafts 
proper.  These  are  practically  always  formed  in  one 
piece  on  tractor  motors,  though  built-up  crank  shafts  in 
which  these  pieces  are  separate  and  fastened  together 
are  sometimes  used  in  light  motors,  such  as  employed 
for  motor-cycle  propulsion. 

A  crank  shaft  such  a.s  would  be  used  on  the  ordinary 
form  of  opposed  motor  is  shown  at  Fig.  50-A  in  its  fin- 
ished condition.  The  bearings  are  exceptionally  long 
and  keyways  are  machined  in  the  shaft  to  receive  the 
keys  for  fly-wheel  retention.  Four-cylinder  crank  shafts 
as  used  in  tractor  engines  usually  have  three  or  five  main 
bearings.  The  three-bearing  crank  shafts  are  used  on 
those  engines  where  the  cylinders  are  cast  in  pairs,  while 


14C 


The  Modern  Gas  Tractor 


the  five-bearing  shafts  as  depicted  in  Fig.  50-B  are  used 
on  motors  having  individual  cylinder  castings.  On 
medium  and  heavy-duty  power  plants,  the  five-bearing 
crank  shaft  is  considered  better  because  it  is  supported 
by  a  bearing  at  the  sides  of  each  crank  throw.  The 
crank  shaft  shown  has  a  flange  forged  integral  at  one  end 
to  which  the  fly-wheel  is  attached  by  bolts. 


Fig.  50. — Crankshafts  for  Multi-cylinder  Motors.  A — Two 
Throw  Crankshaft  With  Timing  Gear  Attached.  B— 
Four  Throw,  Five   Bearing  Shaft. 

Utility  of  Fly=wheel. — The  gasoline  engine  of  the 
one  or  two-cylinder  type  would  not  be  a  practical  power 
producer  without  some  means  of  equalizing  the  uneven 
power  generation.  Energy  must  be  stored  up  to  carry 
the  crank  shaft  and  other  moving  parts  through  the  idle 
strokes  and  this  is  usually  accomplished  by  providing  a 
heavy  wheel  which  will  continue  to  revolve  after  an 
initial  impulse  given  it  no  longer  exists.  A  fly-wheel  is 
usually  a  heavy  cast-iron  member,  having  the  rim, 
spokes  and  hub  cast  integral.  The  larger  diameter  fly- 
wheels do  not  need  as  heavy  rims  as  do  those  where  the 
weight  is  carried  nearer  the  center  of  the  shaft.    The  fly- 


The  Modern  Gas  Tractor  147 

wheel  weight  depends  upon  the  number  of  cylinders  and 
power  of  the  motor.  Assuming  conditions  where  motors 
would  have  the  same  power,  those  having  the  least  num- 
ber of  cylinders  would  require  the  heaviest  fly-wheel. 

As  a  general  rule  about  ninety  to  one  hundred  pounds 
fly-wheel  weight  is  allowed  to  each  horse-power  of  mod- 
erate speed  one  and  two-cylinder  engines.  As  the  num- 
ber of  cylinders  increases,  the  number  of  explosions  and 
the  torque  become  more  uniform  and  the  fly-wheel  weight 
can  be  reduced.  If  a  single-cylinder  engine  of  a  certain 
power  required  a  fly-wheel  of  four  hundred  pounds 
weight,  a  double-cylinder  engine  would  operate  satis- 
factorily with  one  weighing  three  hundred  and  twenty 
pounds  and  a  four-cylinder  motor  would  require  but  two 
hundred  pounds  of  fly-wheel  weight.  Some  of  the  im- 
portant conditions  that  determine  fly-wheel  dimensions 
are  bore  of  the  cylinder,  compression  in  pounds  per  square 
inch,  speed  of  crank-shaft  rotation,  and  method  of  power 
transmission. 

Usually  multiple-cylinder  engines  of  large  bore  have 
fly-wheels  heavier  than  are  actually  needed  in  order 
that  the  engine  may  be  more  easily  started.  Heavy- 
duty  engines  require  heavier  fly-wheels  than  medium- 
duty  types  and  engines  which  must  run  steadily,  such  as 
those  furnishing  power  to  drive  a  dynamo  for  electric 
lighting,  require  heavier  fly-wheels  than  do  motors 
intended  merely  for  traction  purposes.  Fly-wheeLs 
used  on  tractor  engines  are  generally  simple-spoked 
forms  when  made  for  single-cylinder  engines  though  the 
forms  used  for  multiple-cylinder  motors  often  dispense 
with  spokes  and  have  a  solid  web  of  metal  joining  the 
fly-wheel  rim  and  hub. 

It  is  important  that  the  fly-wheel  be  held  to  the  shaft 
in  a  positive  manner.     The  simplest  method  consist>  of 


148  The  Modern  Gas  Tractor 

boring  out  the  fly-wheel  hub  so  it  is  a  tight  fit  on  the 
crank  shaft  and  then  driving  in  a  key  between  the  shaft 
and  hub  into  suitable  keyways  machined  in  these  mem- 
bers to  prevent  the  fly-wheel  from  turning.  A  better 
method  of  fly-wheel  retention  is  outlined  at  Fig.  51.  In 
this  a  flange  is  formed  integral  with  the  crank  shaft  and 
the  fly-wheel  member  is  firmly  secured  to  this  by  means 
of  substantial  retaining  bolts.  When  these  are  properly 
fitted  it  is  practically  impossible  for  the  fly-wheel  to 
become  loose,  as  sometimes  happens  in  the  simple-keyed 
construction. 


Fig.  51. — Typical    Fly- Wheel    and    Method     of     Attaching    to 
Crankshaft  Flange  by  Bolts. 

The  diameter  of  a  fly-wheel  must  be  held  to  certain 
limits  and  the  weight  one  can  put  at  the  rim  is  restricted 
by  the  limits  imposed  on  circumferential  speed.  It  is 
stated  that  a  safe  speed  for  a  cast-iron  pulley  is  about  a 
mile  a  minute  for  any  point  on  its  circumference.     The 


The  Modern  Has  Tractor  14!> 

slower  the  speed  of  the  engine,  the  larger  the  diameter 
of  the  fly-wheel  one  can  use  and  the  more  effective  it 
becomes  as  a  balancing  member.  A  fly-wheel  3  feet  in 
diameter  would  have  a  circumference  of  approximately 
10  feet.  As  any  point  on  the  rim  would  turn  this  dis- 
tance in  a  revolution,  in  order  not  to  exceed  the  safe 
peripheral  speed  the  fly-wheel  should  not  revolve  faster 
than  500  revolutions  per  minute.  If  a  fly-wheel  was  6 
feet  in  diameter  its  circumference  would  be  twice  as  great 
as  the  small  member  previously  mentioned  and  its  speed 
would  be  limited  to  250  revolutions  per  minute. 

Engine  Base  and  Bearings. — All  gasoline  engines 
require  a  substantial  base  member  to  which  the  cylinder 
or  cylinders  are  attached  and  which  supports  the  crank 
shaft  as  well.  The  engine  base  must  be  of  substantial 
construction  in  order  to  keep  all  parts  of  the  motor  in 
alinement  and  will  vary  widely  in  form  depending  upon 
the  type  of  engine.  Engine  bases  used  on  the  simpler 
tractor  power  plants  are  made  of  cast  iron,  though  some 
of  the  engine  bases  used  with  the  multiple-cylinder  en- 
gines of  the  automobile  type  are  made  of  aluminum. 
Cast  iron  is  a  suitable  material  for  this  purpose,  and 
while  it  is  somewhat  brittle  and  unreliable  in  nature 
when  made  in  light  sections,  there  is  not  the  need  for 
saving  weight  in  a  tractor  engine  that  exists  in  automo- 
bile practice,  so  strength  is  obtained  by  using  a  little 
more  iron. 

A  simple  engine  bed  such  as  used  for  a  single-cylinder 
stationary  type  power  plant  is  shown  at  Fig.  52,  and  it 
will  be  noticed  that  the  lower  portion  of  the  crank-shaft 
bearings  are  formed  integral  with  the  engine  bed.  On 
the  multiple-cylinder  engines  the  form  of  the  crank  case 
will  depend  upon  the  number  of  cylinders  and  their  dis- 


150 


The  Modern  Gas  Tractor 


position.  They  are  often  approximately  cylindrical 
members,  which  may  be  divided  horizontally  along  the 
crank-shaft  center  line  or  which  may  be  in  one  piece,  hav- 
ing end  plates  to  support  the  main  bearings  and  large 
openings  through  which  the  interior  mechanism  can  be 
inspected.  It  is  obvious  that  the  diameter  of  the  crank 
case  must  be  large  enough  to  permit  the  crank  shaft 
and  connecting  rod  big  ends  to  turn  inside  of  it,  and  its 
length  is  controlled  by  the  number  of  cylinders  and  their 
arrangement. 


Fig.  52. — Base   for   Single   Cylinder   Heavy   Duty   Motor. 

The  crank  case  of  a  single-cylinder  or  double-opposed 
cylinder,  horizontal  type,  would  be  about  the  same  in 
length.  ■  That  of  a  four-cylinder  engine  will  depend  upon 
the  method  of  casting  the  cylinders.  A  shorter  crank 
case  is  utilized  when  the  cylinders  are  cast  in  pairs  than 
when  individual  cylinder  castings  are  employed.  The 
crank  case  shown  at  Fig.  53  is  a  type  used  on  a  three- 
cylinder  engine  and  is  somewhat  shorter  than  would  be 
necessary  with  four  cylinders.  As  will  be  evident,  it 
consists  of  two  parts.     The  upper  portion  serves  as  the 


The  Modern1  Gas  Tractor 


151 


engine-bed  proper  and  carries  the  cylinders  and  crank 
shaft.  The  arms  by  which  the  engine  is  supported  on 
the  tractor  frame  are  cast  integrally  with  the  upper 
member.  The  lower  portion  of  the  crank  case  serves 
merely  as  an  oil  container  and  cover  for  the  working 
parts  and  may  be  easily  removed  to  permit  thorough 
repairing  of  the  interior  mechanism. 

A  superficial  examination  of  the  parts  is  made  possible 


Fig.  53.— Crankease  of  Russell  Three  Cylinder  Tractor  Motor 
Composed  of  Two  Halves  and  is  Split  Longitudinally  at 
Crankshaft   Center   Line. 

by  means  of  readily  removable  plates  at  the  side  of  the 
crank  case,  though  when  repairs  of  a  serious  nature  are 
made,  such  as  adjusting  the  connecting  rods  or  main 
bearings,  it  is  best  to  remove  the  lower  half  of  the  engine 
base.     A  four-cylinder  crank  case  of  the  barrel  type  is 


151*  The  Modern  Gas  Tractor 

shown  at  Fig.  54.  As  will  be  seen  this  construction  calls 
for  the  use  of  end-bearing  plates,  which  carry  the  front 
and  rear  main  journals,  while  the  three  main  bearings 
inside  the  crank  case  are  attached  to  the  partitions  which 
separate  the  lower  portion  into  four  compartments. 
The  cylinders  are  held  in  place  by  a  series  of  stud  bolts 
screwed  into  the  top  of  the  case.    In  order  to  gain  access 


Fig.  54. — Crankcase    of    Holt    Tractor    Engine,    a    One    Piece 
Casting    With    Removable    Side    Inspection    Plates. 

to  the  interior  large  openings  are  provided  at  both  sides 
of  the  crank  case  and  are  closed  by  substantial  cover 
plates,  such  as  shown  leaning  against  the  engine  base 
when  the  assembly  is  completed.  The  main  object  in 
engine-base  design  is  to  have  the  member  a  substantial 
one  that  will  keep  the  crank  shaft  rigidly  in  line  with  the 
connecting  rods  and  pistons  and  which  will  be  of  such 
design  that  the  various  parts  will  be  accessible  for  inspec- 
tion or  adjustment  without  having  to  dismantle  the  entire 
power  plant. 


CHAPTER  V. 

MAKING  AND  EXPLODING  THE  GAS. 

The  Liquid  Fuels — Gasoline — Kerosene — Alcohol — Elements  of 
Carburetion — Simple  Mixing  Valves — Float  Feed  Carbure- 
tor Action — Automatic  Carburetors — Parts  of  Carburetors 
— Typical  Gasoline  Carburetors — Carburetor  for  Two- 
cycle  Engines — Action  of  Kerosene  Vaporizer — Methods 
of  Exploding  Charge — Advantages  of  Electric  Ignition — 
Methods  of  Producing  Current — Dry  and  Storage  Batteries — 
Function  of  Induction  Coil — Producing  Spark  in  Cylin- 
ders— Mechanical  Generator  Advantages — Types  of  Mag- 
netos— Oscillating  Armature  Forms — Types  with  Revolv- 
ing Armature — True  High  Tension  Device — Low  Tension 
Ignition  System — Simple  Battery  Ignition  Methods — 
Action  of  Magneto   Ignition   System — Timing    the  Spark. 

The  Liquid  Fuels. — The  great  advance  of  the  in- 
ternal combustion  motor  can  be  attributed  more  to 
the  discovery  of  suitable  liquid  fuels  than  to  any  other 
factor.  The  first  gas  engines  made  utilized  ordinary 
illuminating  gas  as  a  fuel,  and  while  this  is  practical 
for  use  with  stationary  power  piants  wherever  it  is 
available,  such  as  the  natural  gas  fields  of  the  Middle 
West,  or  in  cities  and  towns  having  a  central  gas  pro- 
ducing plant,  it  is  obvious  that  it  could  not  be  very 
well  applied  to  portable  self-propelling  power  plants 
used  for  tractor  propulsion.  When  it  was  discovered 
that  certain  of  the  liquid  fuels  belonging  to  the  hydro- 
carbon class,  which  includes  petroleum  and  its  distillates, 
benzol  and  benzene,  which  are  coal  tar  products,  and 
alcohol,  were  suitable,  the  gas  engine  became  widely 
used  as  a  prime  mover. 

153 


154  The  Modern  Gas  Tractor 

The  liquid  fuels  have  the  important  advantage  that 
a  quantity  sufficient  for  an  extended  period  of  engine 
operation  can  be  easily  carried  in  a  container  that  will 
not  tax  the  capacity  of  the  engine  and  that  requires 
but  comparatively  little  space  in  any  out-of-the-way 
portion  of  the  frame.  When  used  in  connection  with 
a  simple  vaporizing  device,  which  mixes  the  liquid  with 
sufficient  quantities  of  air  to  form  an  inflammable  gas, 
the  fuel  is  automatically  supplied  to  the  engine  without 
any  attention  being  demanded  from  the  operator  as 
long  as  the  supply  in  the  tank  is  sufficient  to  produce 
a  flow  of  liquid  through  the  pipe  joining  the  mixing 
device  and  fuel  container. 

Gasoline. — Up-to-date  the  most  important  fuel  used 
in  connection  with  gas  engines  has  been  one  of  the 
distillates  of  crude  petroleum,  known  generally  to  the 
trade  as  "gasoline."  This  liquid,  which  is  a  clear  white 
very  light  bodied  substance,  evaporates  very  rapidly 
at  ordinary  temperatures.  This  feature  made  it  especially 
adaptable  for  use  with  the  early  forms  of  mixing  valves 
because  it  mixed  so  readily  with  air  to  form  an  explosive 
gas.  Fifteen  years  ago  there  were  very  few  industrial 
uses  for  gasoline  and  it  sold  for  less  than  five  cents  a 
gallon  in  some  cases.  During  the  past  decade  the 
demand  for  it  has  increased  by  leaps  and  bounds,  and 
it  now  sells  for  four  times  as  much  as  it  did  when  the 
gasoline  engine  was  first  introduced. 

The  specific  gravity  of  gasoline  varies  from  sixty  to 
seventy-six  degrees,  though  very  little  of  the  latter  is 
now  obtainable  except  by  special  arrangement  with 
the  oil  producing  company.  It  was  formerly  thought 
that  gasoline  any  heavier  than  seventy-six  degrees 
would  not  work  satisfactorily  in  the  cylinders  of  the 
gas  engine,  and  while  this  is  true  of  the  early  crude  and 


The  Modern  Gas  Tractor 


155 


inefficient  vaporizers,  modern  mixing  devices  have  been 
evolved  which  handle  gasoline  of  sixty-two  degrees 
specific  gravity  and  even  heavier.  The  percentage  of 
gasoline  produced  from  crude  oil  in  proportion  to  the 
other  elements  is  very  small,  and  as  the  demand  has 
increased  to  such  proportions,  the  tendency  of  the 
producer  has  been  to  make  gasoline  heavier  or  of  lower 


Grad.  A 


Grad.  B 


Grad.  C 


Fig.  55. — Graduate  A  Shows  Proportion  of  Different  Products 
Obtained  From  Kansas  Crude  Oil.  The  Fractional  Dis- 
tillation of  Gasoline  is  Shown  in  Graduate  B.  Method 
of  Making  Baume  Test  Shown  at  C. 

specific  gravity  by   distilling  off  som?  of  the   heavier 
oils  with  it  to  increase  the  bulk  produced. 

If  one  refers  to  graduate  A  shown  at  Fig.   55,  the 
proportion    of   gasoline    obtained    by    distillation    from 


1 5<>  The  Modern  Gas  Tractor 

crude  petroleum  may  be  easily  learned.  The  term 
"gasoline"  is  now  applied  to  all  products  testing  over 
fifty  deg.  Baume.  Less  than  six  per  cent  of  the  bulk 
of  the  petroleum  base  becomes  light  gasoline  of  over 
sixty-four  degrees.  The  larger  bulk  of  the  petroleum  is 
refined  into  kerosene  which  tests  from  forty  to  fifty 
deg.  Baume.  The  crude  petroleum  is  broken  up  into 
three  main  groups  of  products,  as  follows:  Highly 
volatile,  gasoline,  benzine,  and  naphtha,  eight  to  ten 
per  cent;  light  oil,  such  as  kerosene  and  light  lubri- 
cating oil,  seventy  to  eighty  per  cent;  heavy  oils  or 
residuum,  five  to  nine  per  cent.  In  order  to  make  clear 
the  enormous  consumption  of  gasoline  in  this  country, 
experts  have  estimated  that  if  all  the  internal  combus- 
tion engines  in  use  which  depended  on  this  fuel  were 
to  be  operated  continuously  for  a  day  of  ten  hours, 
over  seven  million  five  hundred  thousand  gallons  of 
liquid  would  be  consumed. 

Kerosene. — In  order  to  understand  thoroughly  the 
action  of  fuels  in  an  internal  combustion  engine  and 
their  value,  one  should  understand  to  some  extent  the 
process  of  distillation  to  which  the  crude  oil  is  subjected. 
The  petroleum  is  pumped  into  a  large  steel  boiler  or 
still,  from  which  a  pipe  leads  to  a  condenser.  The  liquid 
is  gradually  heated,  and  as  the  gas  rising  from  the  crude 
oil  escapes  through  the  condenser,  it  is  cooled  at  this 
point  and  again  becomes  a  liquid.  The  liquid  flowing 
from  the  condenser  is  constantly  tested  with  a  Baume 
tester,  and  as  the  specific  gravity  of  the  distillate  changes 
to  the  different  weights,  the  liquids  are  run  off  into 
separate  storage  tanks. 

The  lighter  liquids  testing  about  eighty  deg.  Baume 
come  off  first,  and  as  the  crude  oil  becomes  hotter  the 
heavier   constituents  are   volatilized   and  the  substance 


The  Modern  Gas  Tractor  157 

coming  from  the  condenser  gradually  becomes  heavier. 
The  process  continues  till  nothing  is  left  of  the  crude 
oil  but  a  species  of  solid  matter  resembling  coke  which 
is  composed  of  carbon  and  the  various  earthy  matters 
that  were  contained  in  the  crude  product.  The  refineries 
obtain  gasoline  varying  in  quality  from  eighty  degrees 
down  to  fifty  degrees,  kerosene  from  fifty  degrees  down 
to  forty  degrees,  distillate  from  forty  degrees  down  to 
twenty-nine  degrees,  and  below  that  lubricating  oils. 
The  various  proportions  are  clearly  shown  in  graduate 
A  at  Fig.  55. 

Kerosene,  as  sold  to-day,  varies  between  forty-two 
deg.  and  forty-five  deg.  Baume.  Heretofore  it  has 
been  the  common  belief  that  because  gasoline  is  more 
easily  evaporated  and  exploded  than  kerosene,  it 
gives  more  power,  but  actually  the  properly  vaporized 
kerosene  contains  more  heat  units  than  gasoline  and 
this  applies  just  as  well  to  the  lower  grades  of  oil  which 
are  sold  under  various  names,  such  as  distillate,  solar 
oil,  fuel  oil,  etc.  The  graduate  at  B,  Fig.  55,  shows  the 
various  proportions  in  which  gasoline  may  be  divided. 
As  will  be  evident  it  consists  of  quite  a  number  of  liquids 
having  different  specific  gravities.  These  are  mixed 
together  and  the  resulting  gasoline  has  a  specific  gravity 
that  is  an  average  of  the  various  grades  mixed  together 
to  form  the  product. 

The  liquid  known  as  kerosene  is  not  composed  of 
such  a  widely  varying  number  of  constituents  as  is 
gasoline  and  it  remains  more  constant  in  quality.  The 
difficulty  which  has  obtained  and  which  has  militated 
against  the  general  use  of  kerosene  has  been  the  diffi- 
culty met  with  in  vaporizing  it  at  ordinary  tempera- 
tures. It  is  practically  impossible  to  start  an  electrically 
ignited  engine  on  kerosene  when  cold.    The  metal  parts 


158  The  Modern  Gas  Tractor 

of  the  combustion  chamber  and  vaporizer  must  first 
be  raised  in  temperature  before  kerosene  can  be  used 
successfully.  The  grades  of  gasoline  now  sold  for  fuel 
will  evaporate  in  winter  without  much  difficulty,  but 
kerosene  will  not  give  off  vapors  unless  heated  to  nearly 
the  boiling  point  of  water. 

Where  kerosene  is  used  for  fuel  it  is  customary  to 
provide  an  auxiliary  gasoline  supply  which  may  be 
used  to  operate  the  engine  until  it  has  become  hot 
enough  to  run  on  the  heavier  fuel.  As  so  large  a  pro- 
portion of  the  crude  oil  yield  is  distilled  into  kerosene 
its  price  is  considerably  lower  than  that  of  gasoline  and 
many  of  the  modern  gas  tractors  are  provided  with  mix- 
ing devices  that  will  use  gasoline  to  start  the  engine 
on  and  then  kerosene  or  distillate  after  the  power 
plant  becomes  heated. 

The  method  of  making  a  Baume  test  is  outlined  at 
Fig.  55-C.  The  tester  is  a  species  of  hydrometer.  This 
consists  of  a  glass  tube  having  an  enlarged  lower  por- 
tion filled  with  air  in  order  that  it  may  float  in  a 
liquid  and  a  small  ball  filled  with  shot  at  the  lower  end 
to  keep  the  device  vertical  in  the  liquid  in  which  it  is 
floated.  The  stem  of  the  hydrometer  is  provided  with 
a  scale,  calibrated  to  read  in  degrees,  and  the  specific 
gravity  of  the  liquid  is  clearly  indicated  and  its  nature 
may  be  easily  determined  by  this  test.  The  stem  will 
sink  lower  in  the  lighter  liquids,  so  the  figures  denoting 
the  liquids  of  higher  specific  gravity  are  nearer  the  top. 

Alcohol. — Gasoline  and  kerosene  are  derived  from 
natural  mineral  deposits  which  will  become  more  and 
more  depleted  as  the  demand  for  the  product  becomes 
greater.  Petroleum  was  formed  ages  ago,  presumably 
from  decaying  vegetation,  and  like  coal  the  supply  is 
not  inexhaustible.      While  there  is  no  immediate  fear 


The  Modern  Gas  Tractor  150 

of  a  petroleum  famine,  considerable  experimenting  is 
being  carried  on  by  engineers  to  attempt  to  use  alcohol 
as  a  substitute  for  the  hydrocarbons  commonly  used 
at  present. 

Alcohol  is  the  one  fuel  that  can  be  produced  in  quan- 
tities that  could  be  increased  as  the  demands  for  it 
augmented.  It  is  produced  by  distilling  various  vege- 
table substances,  and  as  these  are  reproduced  each  cycle 
of  seasons,  the  raw  material  from  which  alcohol  may 
be  manufactured,  in  addition  to  being  found  in  all 
parts  of  the  world,  would  be  renewed  periodically. 
Alcohol  differs  materially  from  gasoline  in  that  it  is 
less  volatile  and  requires  more  heat  to  vaporize  it.  It 
cannot  be  used  successfully  in  engines  designed  for  gas- 
oline or  kerosene  as  higher  degrees  of  compression  than 
are  practical  with  either  of  these  commonly  used  fuels 
must  be  provided  in  order  to  burn  alcohol  efficiently. 

Experiments  have  been  made  with  a  view  of  permitting 
one  to  use  alcohol  in  engines  of  present  design  by  passing 
alcohol  vapor  through  calcium  carbide  before  it  enters 
the  cylinder.  As  alcohol  contains  water,  this  substance 
liberates  acetylene  gas  when  it  comes  in  contact  with 
the  carbide  and  the  resulting  alcohol-acetylene  gas  can 
be  burned  in  engines  of  conventional  design  and  satis- 
factory results  obtained. 

The  fire  risk  with  alcohol  is  much  less  than  with 
either  gasoline  or  kerosene,  as  while  water  only  serves 
to  spread  burning  petroleum  products,  it  will  extinguish 
an  alcohol  fire.  Some  authorities  contend  that  alcohol 
will  be  the  fuel  of  the  future,  but  in  this  work  the  writer 
intends  to  deal  only  with  practical  matters  of  to-day 
so  that  but  brief  mention  of  the  character  and  possibili- 
ties of  alcohol  as  fuel  is  considered  necessary. 

Elements  of  Carburetion. — Carburetion  is  a  pro- 


1(50  The  Modern  Gas  Tractor 

cess  of  combining  the  volatile  vapors  evaporating  from 
the  hydrocarbons  previously  mentioned  with  enough 
air  to  form  an  inflammable  gas.  The  amount  of  air 
needed  varies  with  the  character  of  the  liquid  fuel  and 
some  mixtures  burn  much  quicker  than  others.  If  the 
fuel  and  air  mixture  is  not  properly  proportioned  the 
rate  of  burning  will  vary  and  either  an  excess  of  fuel  or 
air  will  reduce  the  power  obtained  from  combustion 
materially.  The  proportions  of  air  and  liquid  needed 
vary  according  to  the  chemical  composition  of  the 
liquid. 

Gasoline,  which  is  that  commonly  used  at  the  present 
time,  is  said  to  comprise  84  per  cent  carbon  and  16 
per  cent  hydrogen.  Oxygen  and  nitrogen  form  the 
main  elements  of  the  air  and  the  former  has  a  great 
attraction  for  the  main  constituents  of  hydrocarbon 
liquids.  What  we  call  an  explosion  is  merely  an  indica- 
tion that  the  oxygen  of  the  air  has  combined  with  the 
carbon  and  hydrogen  of  gasoline.  In  figuring  the 
proper  amount  of  air  to  mix  with  a  given  quantity  of 
fuel  one  takes  into  account  the  fact  that  eight  pounds 
of  oxygen  are  required  to  burn  one  pound  of  hydrogen 
and  that  two  and  one-third  pounds  of  oxygen  are  neces- 
sary to  insure  the  combustion  of  one  pound  of  carbon. 
As  air  is  composed  of  one  part  of  oxygen  and  three  and 
one-half  portions  of  nitrogen  by  weight,  for  each  pound 
of  oxygen  one  needs  to  burn  either  hydrogen  or  carbon, 
four  and  one-half  pounds  of  air  must  be  allowed.  About 
sixteen  pounds  of  air  must  be  furnished  to  insure  com- 
bustion of  one  pound  of  gasoline,  the  hydrogen  consti- 
tuent requiring  six  pounds  of  air  while  the  carbon  com- 
ponent needs  ten  pounds  of  air. 

Air  is  not  usually  considered  as  having  much  weight, 
but  at  a  temperature  of  62  deg.  Fahr.  fourteen  cubic 


The  Modern  (Ias  Tractor  Itil 

feet  of  air  will  weigh  a  pound.  Two  hundred  cubic 
feet  of  air  will  be  needed  to  burn  a  pound  of  gasoline 
according  to  theoretical  considerations.  The  element 
nitrogen,  which  is  the  main  constituent  of  air,  is  a 
deterrent  to  burning  as  it  does  not  aid  combustion  or 
burn  itself.  Therefore,  it  is  usual  practice  to  provide 
four  hundred  cubic  feet  of  air  to  each  pound  of  gasoline. 
Mixtures  varying  from  one  part  of  gasoline  vapor  to 
from  four  to  thirteen  parts  of  air  can  be  ignited,  but 
the  best  results  are  obtained  when  five  to  seven  parts 
of  air  are  combined  with  one  of  gasoline  vapor.  This 
mixture  produces  the  most  rapid  combustion,  the  high- 
est temperature  and,  consequently,  the  most  pressure. 
Simple  Mixing  Valve. — All  devices  that  will  mix 
gasoline  vapor  and  air  in  proper  proportions  so  the 
mixture  will  burn  are  called  vaporizers.  This  general 
class  may  be  divided  into  two  distinct  types  of  car- 
buretor. The  simplest  of  these  is  termed  a  mixing  valve 
and  its  principle  of  operation  is  very  easily  understood. 
A  sectional  view  of  a  typical  simple  mixer  is  shown 
at  Fig.  56.  It  consists  of  a  cast  bronze  body  in  the 
shape  of  an  elbow  having  a  valve  seat  machined  about 
half  way  in  its  interior.  A  mushroom  valve  seats 
against  the  brass  body  and  separates  the  device  into 
two  parts,  as  the  valve  head  is  held  normally  in  contact 
with  the  valve  seat  by  means  of  a  light  coil  spring. 
The  fuel  supply  is  led  to  a  small  branch  member  at- 
tached to  one  side  of  the  main  body  of  the  mixing  valve 
and  having  a  small  passage  that  communicates  with 
one  of  the  walls  of  the  valve  seating  member.  The 
area  of  this  passage  is  regulated  by  a  needle  valve  which 
may  be  turned  conveniently  by  a  large  knurled  head. 
The  passage  is  normally  kept  closed  by  the  head  of 
the  mushroom   valve.     The  device  is  attached   to  the 


1C.2 


The  Modern  Gas  Tractor 


engine  at  the  connection  marked  "Mixture  outlet"  and 
the  other  end  has  free  access  to  the  air. 

When  the  piston  draws  in  a  charge  of  air  on  its  intake 
stroke  it  will  open  the  air  valve  which  at  the  same  time 
uncovers  the  gasoline  spray  passage  and  a  stream  of 
gasoline   mixes   with   the   incoming  air   current  and   is 


ai  r  valve: 

AIR 


5 PRAY  PASSAGE! 


MIXTURE  OUTLET 


Fig.  56. — Sectional  View  of  Simple  Vaporizer  Valve. 

vaporized  when  it  reaches  the  interior  of  the  cylinder. 
As  soon  as  the  inlet  valve  of  the  motor  closes,  the  small 
air  valve  of  the  mixing  device  is  returned  to  its  seat 
by  the  coil  spring  and  both  air  and  gasoline  passages 
are  shut  off  simultaneously.  The  mixture  proportions 
may  be  regulated  by  varying  the  amount  of  gasoline 


The  Modern  Gas  Tractor 


163 


supplied,  which  is  done  by  altering  the  area  of  the  spray 
passage  with  the  needle  point  of  the  gasoline  regulating 
valve. 

Another  simple  mixing  valve  which  combines  a  suc- 
tion gasoline  feed  from  a  tank  placed  lower  than  the 
intake  valve  is  outlined  at  Fig.  57.  In  the'device  shown 
at  Fig.   56  it  is  necessary  to  place  the  gasoline  tank 


Pig.  57. — Sectional    View    Explaining    Action    of    Gray    Fuel 
Vaporizer. 


1H4  The  Modern  (Ias  Tractor 

higher  than  the  vaporizer  body  and  depend  upon  a 
gravity  feed.  This  means  that  the  gasoline  supply 
must  be  shut  off  every  time  the  engine  is  stopped,  in 
order  to  prevent  flooding.  When  a  suction  feed  is  used, 
the  gasoline  supplied  the  vaporizer  stops  flowing  auto- 
matically when  the  engine  stops.  When  the  piston  A 
moves  forward  a  partial  vacuum  in  the  firing  chamber 
B  is  created.  This  causes  the  inlet  valve  E  to  lift  from 
its  seat  D  and  air  rushes  into  the  combustion  chamber 
through  the  supply  pipe  I  and  then  past  the  inlet  valve 
E.  The  air  pipe  is  restricted  around  the  spray  nozzle 
Q  so  that  the  air  rushing  past  this  point  must  flow 
faster  on  account  of  the  constricted  passageway  and 
considerable  suction  is  present  at  the  point  of  the  spray 
nozzle.  Thus  when  the  needle  valve  H  is  opened  slightly 
gasoline  from  the  tank  T  passes  up  the  fuel  feed  pipe 
K  and  is  sprayed  into  the  chamber  F  where  it  mixes 
with  the  air  current  and  the  resulting  vapor  is  drawn 
into  the  combustion  chamber  B  by  the  vacuum  created 
by  the  piston.  A  check  valve  is  placed  in  the  gasoline 
pipe  at  J  so  the  level  of  gasoline  will  remain  at  that 
point  while  the  engine  is  running.  When  the  piston 
reaches  the  end  of  its  suction  stroke  the  valve  E  closes 
and  the  gases  in  the  compression  chamber  are  compacted 
and  fired  at  the  proper  point  by  an  electric  spark. 

Float  Feed  Carburetor  Action. — The  simple  mix- 
ing valve  forms  have  disadvantages  of  some  moment, 
the  main  defect  being  that  they  are  somewhat  erratic 
in  action  and  that  the  mixture  cannot  be  as  well  regu- 
lated as  when  float  feed  carburetors  are  used.  While 
the  primitive  forms  gave  fairly  good  results  with  high 
grade  gasoline  they  do  not  carburate  the  lower  grades 
of  fuel  used  to-day  properly  and  do  not  supply  enough 
gas  of  proper  consistency  for  the  present  types  of  engines. 


The  Modern  Gas  Tractor  165 

The  most  efficient  modern  power  plants  utilize  float 
feed  carburetors  instead  of  simple  mixing  valves.  The 
advantage  of  the  float  construction  is  that  the  gasoline 
is  maintained  at  a  constant  level  regardless  of  engine 
speed.  In  the  simple  forms  of  generator  valves  in 
which  the  gasoline  opening  is  controlled  by  a  poppet 
valve  a  leak  in  either  valve  or  valve  seat  will  allow  the 
fuel  to  flow  continuously  whether  the  engine  is  drawing 
in  a  charge  or  not.  During  the  idle  strokes  of  the  piston 
when  there  is  no  suction  effect  exerted  to  draw  in  gaso- 
line vapor,  the  liquid  fuel  will  collect  around  the  air 
opening,  and  when  the  engine  does  draw  in  a  charge  it 
is  excessively  rich  because  it  is  saturated  with  globules 
of  liquid  fuel. 

With  a  float  feed  construction  a  constant  level  of 
gasoline  or  other  fuel  is  maintained  at  the  right  height 
in  the  stand  pipe,  and  will  only  be  drawn  out  of  the  jet 
by  the  suction  effect  of  the  entering  air  stream.  The 
objection  to  the  simple  mixing  valves  utilizing  suction 
feed  is  that  the  tendency  is  to  draw  off  only  the  more 
volatile  constituents  of  the  fuel  and  that  after  a  time 
the  heavier  elements  comprising  gasoline  will  remain 
in  the  container  and  will  not  be  properly  vaporized. 
Obviously  the  engine  is  not  capable  of  utilizing  all  of 
the  fuel.  With  a  float  controlled  spray  nozzle  the 
spray  is  composed  of  all  the  constituents  of  the  liquid 
and  the  lower  grade  portions  that  are  mixed  with  those 
having  higher  evaporation  points  are  drawn  into  the 
cylinder  and  burnt  instead  of  settling  to  the  bottom  of 
the  tank. 

The  simplest  form  of  float  feed  carburetor  is  shown 
at  Fig.  58.  In  this  the  principle  of  mixing  the  gasoline 
vapor  and  air  is  the  same  as  in  the  simpler  mixing 
devices   but   the   method    of   fuel   supply  is     different. 


166 


The  Modern  <Jas  Tractor 


The  device  consists  of  two  parts,  a  float  chamber 
and  a  mixing  chamber.  The  standpipe  in  the  mix- 
ing chamber  is  connected  to  the  float  chamber  and 
the  arrangement  is  such  that  the  level  of  liquid  in 
the  float  chamber  is  kept  to  a  height  equal  to  that 
of  the  spray  nozzle.  The  method  by  which  this  may 
be  accomplished  is  clearly  shown  at  Fig.  58.  The  fuel 
pipe  from  the  tank  or  main  container  is  coupled  to 
the  top  of  the  float  chamber  and  the  opening  is  closed 


inlet  Value' 


Hollow  Metal  Float 

■  Used  to  Regulate 

Height  of  Fuel 


Air  Opening 


Gasoline 

Pipe  Connecting 
Float  Chamber 
and  Jet 


Fig.  58. — Diagram  Showing  Action  of  Float  Feed  Carburetor 
Evolved  by  May  bach. 


by  means  of  a  needle  point  carried  by  a  hollow  metal 
float.  The  length  of  the  needle  is  such  that  its  point 
shuts  off  the  gasoline  supply  when  the  level  of  gasoline 
in  the  float  chamber  coincides  with  the  top  of  the  stand- 
pipe.  Whenever  the  fuel  is  drawn  out  of  the  float  cham- 
ber sufficiently  fast  so  the  level  is  reduced,  the  hollow 
float  will  sink  with  the  decreasing  liquid  and  the  passage 
in  the  fuel  supply  pipe  is  opened,  allowing  gasoline  to 
flow  into  the  float  chamber  until  the  liquid  is  at  the 
proper  height.    Just  as  soon  as  the  proper  level  is  reached 


The  Modern  Gas  Tractor 


107 


the  float  and  the  needle  it  carries  are  raised  until  they 
shut  off  the  flow  of  gasoline  from  the  tank. 

Automatic  Carburetors. — The  simple  form  of  float 
feed  spraying  carburetor  has  disadvantages  that  made 
improvements  in  construction  necessary  before  it  became 
really  efficient.  One  of  these  was  that  as  the  engine 
speed  increased  the  suction  effect  augmented  in  pro- 
portion, and  as  more  gasoline  was  sprayed  into  the 
mixture  because  of  the  higher  degree  of  vacuum  created 


Throttle  Valve  Stop, 


Float  Controlled 
Shut  Off  Value  —1. 


Shut  Off  Value'' 
Operating  Leuer 


Auxiliary  Air 
Inlet 


Fuel  Supply  \ 


-Spring  Tension 

'Adjustment 

Cork  Float 
Main  Air  Inlet 


Gasoline  Adjusting  Needle 


Pig.  59. — Sectional    View   of   Modern    Concentric   Float    Auto 
matic  Carburetor. 


168  The  Modern  Gas  Tractor 

in  the  cylinder,  the  mixture  became  too  rich  at  high 
speed.  This  is  the  main  reason  for  the  introduction  of 
the  modern  automatic  carburetor,  such  as  shown  at 
Fig.  59.  In  this  device  the  needle  valve  is  mounted 
concentric  with  the  float,  i.  e.,  the  mixing  chamber 
passes  through  the  center  of  the  carburetor,  while  the 
bowl,  in  which  a  circular  float  is  placed,  surrounds  the 
mixing  chamber.  The  air  pipe  is  constricted  around 
the  spray  nozzle  in  order  to  get  the  proper  air  speed 
to  insure  positive  suction  of  liquid  at  low  engine  speeds. 
At  high  engine  speeds,  when  the  mixture  would  be 
too  rich  in  the  simple  form  of  carburetor,  an  automatic 
auxiliary  air  valve,  which  is  carried  to  one  side  of  the 
mixing  chamber,  opens  and  admits  air  to  the  mixture 
to  dilute  it. 

The  concentric  float  chamber  feature  insures  a  con- 
stant level  of  fuel  at  the  nozzle.  When  the  nozzle  is 
carried  at  one  side  of  the  float  chamber,  if  the  carbu- 
retor tilts,  as  is  possible  when  a  tractor  is  running  on 
rough  ground,  or  climbing  or  descending  a  grade,  if 
the  float  chamber  is  higher  than  the  nozzle  the  car- 
buretor will  flood.  If  conditions  are  reversed  the  level 
of  fuel  in  the  spray  nozzle  will  not  be  high  enough, 
and  the  mixture  will  be  too  thin.  With  the  spray 
nozzle  placed  at  the  central  point  of  the  device,  no 
reasonable  amount  of  tilting  will  change  the  height  of 
the  liquid  at  that  point  and  a  mixture  of  constant 
proportions  is  insured  under  all  abnormal  as  well  as 
normal  operating  conditions. 

Parts  of  Carburetors. — Outside  of  the  main  body 
of  the  device,  the  important  parts  of  the  carburetor 
are  the  spray  nozzle  or  jet,  the  float  mechanism,  and 
the  auxiliary  air  valve.  Three  types  of  spray  nozzle 
are  shown  at  Fig.  60.     That  at  A  is  the  simplest  form, 


The  Modern  Gas  Tractor 


169 


and  the  amount  of  fuel  supplied  the  mixture  is  deter- 
mined by  the  size  of  the  opening  through  which  the 
gasoline  issues.  With  this  form  of  nozzle  it  is  not 
possible  to  regulate  the  gasoline  supply  and  all  mixture 
changes  must  be  made  by  altering  the  amount  of  air 
admitted.  With  the  spray  nozzle  shown  at  B  and  C 
very  close  regulation  is  possible  because  the  spray 
opening  is  controlled  by  a  needle  pointed  valve.  At 
B  the  valve  is  at  the  top  of  the  spray  nozzle,  while  at 


Needle  Value 


t 


4 


Needle  Value 


Pig.  60. — Showing:  Forms  of  Spraying  Nozzles  Used  in  Gasoline 
Carburetors. 

C  it  comes  up  through  the  spray  nozzle  interior.  Some 
authorities  contend  that  the  method  outlined  at  B  is 
superior  because  the  needle  point  tends  to  break  up  the 
spray  more  than  when  the  needle  valve  comes  up  from 
the  bottom.  With  the  type  of  nozzle  shown  at  A  the 
fuel  issues  in  a  solid  stream  instead  of  a  spray  and  the 
mixture  is  not  so  intimate  as  when  the  issuing  gasoline 
is  broken  up  into  a   mist   by  the  needle  points.     The 


170 


The  Modern  Gas  Tractor 


amount  of  gasoline  supplied  the  mixture  may  be  regulated 
with  minute  exactness  with  either  form  of  needle  valve, 
and  practically  all  of  the  modern  successful  carburetors 
of  American  design  employ  this  system  of  fuel  regula- 
tion. 

Float  chambers  vary  widely  in  form  from  very  simple 
types  to  others  using  more  or  less  complicated  balancing 
systems  of  needle  valve  control.  Two  simple  forms  of 
float  chamber  which  are  sufficient  to  explain  the  prin- 


Fig.  61. — Float    Chambers   Used   in    Carburetors    to    Maintain 
Constant  Level  at  the  Jet. 

ciples  of  action  are  shown  at  Fig.  61.  In  that  depicted 
at  A  a  cork  float  carries  a  needle  valve  at  its  center 
which  closes  the  gasoline  opening  at  the  top  of  the  car- 
buretor when  the  proper  level  is  reached.  In  the  form 
outlined  at  B  the  liquid  is  admitted  through  the  bottom 
of  the  float  chamber  and  a  system  of  leverage  is  neces- 
sary to  lift  the  balanced  needle  valve  when  the  hollow 
metal  float  falls. 

The  fuel  control  floats  are  usually  either  one  of  the 
two  forms  shown.  Some  authorities  favor  one  method 
of  construction,  while  others  believe  that  the  other  form 


The  Modern  Gas  Tractor 


171 


of  float  offers  the  greatest  advantages.  The  cork  float 
is  the  simplest  and  cheapest  and  is  efficient  as  long  as 
it  does  not  become  soaked  with  fuel  and  too  heavy. 
The  hollow  metal  float  functions  satisfactorily  as  long 
as  it  remains  tight.  If  the  cork  float  becomes  saturated 
with  liquid  it  will  sink  lower  in  the  fuel  and  the  level 
of  gasoline  will  become  too  high.  A  small  leak  in  the 
hollow  metal  float  will  produce  the  same  results  by 
permitting  it  to  fill  with  fuel.  Either  form  is  used  suc- 
cessfully,   though     most    of    the    American    carburetor 


Adjustment 


Spring 


B 


Fig.  62. — Types  of  Automatic  Valves  to  Admit  Auxiliary  Air 
to  Mixture. 

manufacturers  seem  to  favor  the  cork  float  because  it 
is  the  simplest,  cheapest  and  gives  very  good  satisfac- 
tion. 

Auxiliary  air  valves  dc  not  vary  much  in  form,  though 
two  methods  of  construction  are  followed,  as  outlined 
at  Fig.  62.  That  at  A  is  a  flat  seated  leather  disc  valve 
which  is  held  against  its  seat  by  means  of  an  internal 
spring.  The  auxiliary  valve  shown  at  B  is  the  ordinary 
bevel  seated  mushroom  type  of  metal  and  is  retained 
against  its  seat  by  an  external  spring.  In  most  cases 
some  form  of  adjustment  to  regulate  the  supply  of 
auxiliary    air   is   provided.      This   may   be   done   either 


172 


The  Modern*  Gas  Tractor 


by  increasing  the  tension  of  the  spring  or  by  some  form 
of  stop  that  will  restrict  valve  movement.  In  some 
carburetors,  such  as  that  shown  at  Fig.  63,  the  auxiliary 
air  is  admitted  through  a  series  of  ports  closed  by 
bronze  balls  of  varying  weight.  The  lighter  ones  are 
raised    from    their    seats    under    the    influence    of    light 


Zf 


2Z 


ZLO 


m'K.WK.w.wy\w.v 


Fig.  63. — Automatic    Carburetor   Used    on    Holt    Tractor. 

suction,  and  the  heavier  ones  follow  progressively  as 
the  'speed  of  the  engine  and  degree  of  suction  increases. 
Typical  Gasoline  Carburetors. — The  carburetors 
used  on  the  conventional  forms  of  gas  tractors  are  now 
practically  all  of  the  automatic  compensating  type. 
That  shown  at  Fig.  63  is  the  device  used  on  the  Holt 


The  Modern  (tas  Tractor  173 

tractor.  It  is  a  concentric  float  form  having  gasoline 
regulation  by  means  of  a  needle  valve  and  auxiliary 
air  supply  by  means  of  a  series  of  ports  of  varying 
sizes  closed  by  balls  which  lift  progressively  as  the 
suction  increases.  The  gasoline  enters  through  the 
pipe  16  and  its  flow  is  controlled  by  the  needle  valve 
9  which  is  pressed  against  the  seat  10  by  means  of  the 
lever  11  which  fulcrums  at  23  and  which  is  attached 
to  the  cork  float  8.  When  the  level  of  gasoline  in  the 
float  chamber  22  reaches  the  height  of  the  top  of  the 
standpipe  3,  the  upward  motion  of  the  float  8  imparts 
a  downward  motion  to  the  needle  valve  9  and  brings  it 
against  the  seat  10.  The  main  air  entrance  is  at  12  and 
all  air  entering  into  the  mixture,  whether  it  flows  through 
the  central  air  pipe  or  through  the  auxiliary  passages, 
must  enter  through  this  opening.  The  device  is  coupled 
to  the  induction  pipe  at  6  and  when  the  piston  draws 
in  a  charge  of  gas  it  is  composed  of  air  drawn  through 
12  and  gasoline  sprayed  from  the  nozzle  3.  When  the 
speed  of  the  engine  increases  and  more  air  is  needed 
the  auxiliary  air  supply  enters  the  mixing  chamber 
through  the  passages  5  which  surround  the  central 
air  pipe  4. 

Another  form  of  carburetor,  which  is  used  on  the 
Hart-Parr  tractor,  is  shown  at  Fig.  64.  This  view 
shows  not  only  the  carbureting  device  but  the  throt- 
tling governor  that  is  used  to  regulate  the  engine  speed. 
The  gasoline  is  carried  in  the  container  (shown  for  con- 
venience above  the  mixing  device)  and  is  supplied  to 
the  float  chamber  of  a  concentric  carburetor  through 
the  usual  form  of  float-controlled  valve.  Before  the 
liquid  enters  the  float  compartment  it  must  pass  through 
a  strainer  to  remove  any  foreign  matter  that  may  be 
present.     The  gasoline  spray  nozzle  is  controlled  by  a 


174 


The  Modern  Gas  Tractor 


Fig.  64. — Carburetor  and  Governor  of  Hart-Parr  Design. 

regulating  valve  having  a  needle  point  and  the  amount 
of  gasoline  supplied  the  mixture  may  thus  be  easily 
regulated.  The  air  is  drawn  in  through  the  vertical 
air  admission  pipe,  the  lower  portion  of  which  is  con- 
trolled by  an  air  valve  which  opens  against  spring 
resistance.      In  addition  to  regulating  the   amount   of 


The  Modern  Gas  Tractor 


175 


gasoline  the  mixture  proportions  may  be  altered  by 
the  air  valve  regulator  provided,  which  increases  the 
tension  of  the  spring  and  thus  limits  the  lift  of  the 
valve. 

Before  the  gas  can  flow  into  the  admission  manifold, 
it  must  pass  through  a  throttle  of  the  piston  type. 
This  is  connected  to  a  centrifugal  governor  in  such  a 
way  that  as  the  governor  weights  fly  out,  due  to  in- 


Fig.  65.— Practical   Method   of   Supplying   Fuel   to   Ellis   Two 
Cycle  Engine. 

creased  speed,  they  draw  down  on  the  throttle  valve 
regulating  spindle  and  close  the  valve,  this  reducing 
the  amount  of  gas  taken  into  the  cylinder  and  cutting- 
down  the  engine  speed  proportionately.  A  simple 
speed  adjuster  is  provided,  so  that  the  amount  of  pis- 
ton valve  travel  in  relation  to  the  spreading  out  of  the 
governor  weights  can  be  varied  at  will. 

Carburetor    for    Two=cycle    Engine. — A     typical 


17<>  The  Modern  (Ias  Tractor 

mixing  device,  as  sometimes  supplied  with  two-cycle 
engines,  is  shown  at  Fig.  65.  This  is  based  on  the  fuel 
injection  principle  and  while  it  is  not  used  at  the  present 
time  on  a  tractor  power  plant,  the  principle  of  opera- 
tion is  a  valuable  one  and  is  given  because  it  illus- 
trates clearly  another  possible  method  of  vaporizing  the 
liquid  fuel.  The  vaporizer  shown  is  used  on  the  Ellis 
two-cycle  stationary  power  plant  and  has  proven  to 
be  very  practical  and  efficient.  The  device  has  three 
principal  parts:  the  fuel  reservoir,  the  atomizing  disk, 
and  the  heating  chamber.  In  order  that  the  action  be 
more  easily  understood,  the  fuel  reservoir  is  shown 
to  one  side  of  the  engine,  instead  of  in  the  position  it 
actually  occupies.  This  reservoir  has  a  heavy  plate  glass 
body,  through  which  the  fuel  level  can  easily  be  seen. 
An  air  pipe  leading  from  the  lower  part  of  the  cylinder 
is  connected  to  the  top  of  the  reservoir,  while  two  pipes 
are  attached  to  the  bottom  of  the  float  chamber.  One 
of  these  is  the  supply  pipe,  leading  from  the  fuel  tank, 
while  the  other  joins  the  bottom  of  the  fuel  reservoir 
to  the  seat  of  the  atomizing  disk.  The  amount  of  fuel 
passing  to  the  disk  is  regulated  by  a  needle  valve. 
The  cork  float  and  the  fuel  reservoir  shut  off  the  supply 
of  fuel  when  the  level  reaches  the  proper  height  as 
previously   described. 

As  the  piston  moves  upward  in  the  cylinder  it  produces 
a  suction  in  the  fuel  reservoir,  this  drawing  up  a  supply 
of  liquid  from  the  tank  until  the  fuel  reservoir  is  filled 
to  the  proper  level.  When  the  piston  moves  down- 
ward, creating  compression  in  the  top  of  the  fuel  reser- 
voir, the  liquid  is  prevented  from  returning  to  the  tank 
by  a  ball  check  valve.  The  atomizing  disk  regulates 
the  proportions  of  air  and  fuel  and  positively  shuts  off 
the  liquid  when  the  current  of  air  stops.     It  also  va- 


The  Modern  Gas  Tractor  177 

porizes  the  liquid  by  allowing  it  to  be  injected  under 
pressure  into  the  moving  current  of  air  from  the  by- 
pass. The  liquid  is  thus  converted  into  a  fine  mist, 
and  the  vaporized  fuel  and  air  are  then  drawn  into  and 
exposed  to  the  intense  heat  of  the  heating  chamber. 
Thus  carburetion  is  effected  by  a  combination  of  me- 
chanical atomization  and  a  vaporizing  effect  due  to 
heat. 

Just  before  the  transfer  port  is  opened  by  the  piston 
on  its  downward  stroke,  the  lower  edge  of  the  piston 
uncovers  the  end  of  the  air  pipe  leading  to  the  fuel 
reservoir  and  the  compressed  air  which  is  trapped  into 
the  top  of  the  float  chamber  forces  the  liquid  fuel  through 
the  opening  in  the  seat  of  the  atomizing  disk.  As  the 
piston  uncovers  the  transfer  port,  the  compressed  air 
in  the  crank  case,  which  has  been  drawn  in  through  a 
suitable  valve  when  the  piston  was  on  its  up  stroke, 
rushes  past  the  atomizing  disk  and  atomizes  the  fuel 
forced  in  from  the  fuel  reservoir.  The  mixture  of  air 
and  liquid  vapor  is  then  directed  to  the  top  of  the  cylin- 
der by  the  deflector  on  the  piston  head.  The  action 
is  the  same  as  in  any  two-cycle  engine,  one  explosion 
being  obtained  each  revolution  of  the  crank  shaft. 

Action  of  Kerosene  Vaporizer. — In  order  to  insure 
proper  combustion  of  kerosene  when  used  in  carburetors 
of  the  conventional  form,  it  is  necessary  to  start  the 
engine  on  gasoline,  until  all  parts  are  thoroughly  heated. 
If  proper  means  are  taken  to  heat  the  carburetor  and 
the  intake  manifold  to  prevent  condensation  of  kero- 
sene, it  may  be  used  just  as  soon  as  the  various  working 
parts  have  been  properly  heated.  A  float  feed  carbu- 
retor of  conventional  design  arranged  to  burn  kerosene 
is  shown  at  Fig.  66.  It  will  be  noted  that  the  float  cham- 
ber is  surrounded  by  a  jacket,  through  which  hot  water 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  170 

can  enter  at  Q  and  pass  out  at  H,  this  heating  all  parts 
of  the  float  chamber.  The  kerosene  enters  the  device 
through  the  connection  F  and  passes  into  the  float 
chamber  through  the  usual  form  of  float  controlled 
valve. 

In  the  ordinary  automatic  carburetor,  as  the  speed 
increases  and  the  tendency  is  to  draw  in  more  fuel,  an 
automatic  air  valve  opens  to  admit  an  auxiliary  supply 
of  air  to  dilute  the  liquid.  The  carburetor  illustrated 
utilizes  the  auxiliary  valve  in  a  different  manner.  The 
spray  nozzle,  instead  of  being  the  conventional  form, 
is  a  small  standpipe  having  numerous  fine  holes  on 
one  side  and  it  is  called  a  spray  turret.  This  is  shown 
at  A.  At  the  bottom  of  the  spray  member  the  float 
bowl  upper  wall  is  shaped  in  such  a  way  that  a  small 
pool  of  liquid  fuel  is  allowed  to  collect  in  the  bottom. 
The  main  air  intake  is  divided  and  is  alone  sufficient 
only  to  run  the  motor  idle.  The  air  that  enters  the 
primary  intake  passes  directly  over  the  pool  of  fuel 
and  a  rich  mixture  is  obtained  for  starting  on.  The 
auxiliary  air  enters  through  the  opening  D  and  before 
it  enters  the  cylinders  it  must  pass  the  spray  turret. 
This  lifts  the  fuel  up  in  the  standpipe,  where  it  is  drawn 
through  the  fine  holes  in  the  form  of  a  spray.  The 
greater  the  amount  of  air  that  is  passing  through,  the 
higher  the  fuel  rises  in  the  spray  turret,  until  with 
the  throttle  wide  open  it  is  sprayed  from  all  the  holes 
in  the  standpipe,  as  indicated  at  B.  The  condition 
with  a  partially  opened  throttle  is  shown  at  sectional 
view  A  and  it  will  be  noticed  that  the  kerosene  spray 
is  coming  through  only  the  holes  at  the  lower  part  of 
the  standpipe.  The  amount  of  liquid  sprayed  into  the 
mixture  is  regulated  by  the  needle  valve  C.  In  order 
to  burn  kerosene  successfullv  water  is  introduced  into 


180 


The  Modern  Gas  Tractor 


c3 

— 


<D 


3  s 

o  a 


d  O 


— 

— • 

o 

>> 

c 

-O 

£ 

Tl 

~ 

:.. 

0> 

o 

w 

= 

3 

a  a 


The  Modern  Gas  Tractor  181 

the  mixture  through  the  auxiliary  spray  nozzle  I.  This 
supplies  an  extra  amount  of  oxygen  and  insures  a 
more  complete  combustion  of  the  kerosene  vapor  than 
would  be  the  case  if  just  air  was  used. 

Another  method  of  using  the  cheaper  liquid  fuels  is 
shown  at  Fig.  67,  though  this  is  seldom  used  except 
on  stationary  engines  designed  to  run  at  a  constant 
speed.  The  liquid  is  injected  into  the  hot  C3'linder  head 
through  a  special  fitting  when  the  piston  reaches  the 
top  of  its  stroke,  and  as  the  fuel  strikes  the  vaporizing 
spoon,  which  projects  into  the  combustion  chamber, 
it  is  vaporized  on  account  of  the  intense  heat  of  that 
part.  The  action  of  the  engine  is  based  on  the  two- 
stroke  principle.  A  charge  of  pure  air  is  drawn  into 
the  crank  case  when  the  piston  is  going  up  on  the  com- 
pression stroke.  After  the  liquid  is  injected  into  the 
combustion  chamber,  the  heat  which  is  present  at  the 
end  of  the  compression  stroke  is  sufficiently  high  to 
explode  the  charge  of  gas  without  any  other  means 
of  supplying  heat.  To  start  the  motor  the  bulb  at  the 
end  of  the  cylinder  head  is  heated  by  the  flame  of  a 
gasoline  or  alcohol  torch  until  it  reaches  the  proper 
temperature  for  firing  the  charge.  After  the  engine 
is  once  started  the  heat  is  furnished  by  the  successive 
explosions. 

Secor=Higgins  Kerosene  Carburetor. — The  fuel 
supply  system  of  the  Rumely  "Oil  Pull"  tractors  is 
arranged  so  that  kerosene,  distillate  and  other  low 
grade  oils  may  be  burned  successfully.  This,  the  Secor 
system,  so  named  after  its  inventor,  does  not  involve 
specially  designed  engines  as  any  motor  intended  for 
operation  on  gasoline  can  be  used  successfully  with 
kerosene  if  fitted  with  a  Secor-Higgins  carburetor. 
This  is  not  a  new  system,  by  any  means,  because  it 


1X2  The  Modern  Gas  Tractor 

was  developed  over  fourteen  years  ago  and  has  received 
practical  application  in  thousands  of  power  plants 
used  for  agricultural  purposes  during  this  period.  The 
following  matter,  reproduced  from  the  "Scientific 
American  Supplement,"  clearly  outlines  the  essential 
features  of  the  Secor  system  and  also  of  the  vaporizer 
used   in   connection   with   it: 

" Stated  in  brief  terms,  the  system  covers:  (1)  An 
automatic  variation  in  the  quantity  of  fuel  mixture  in 
accordance  with  the  slightest  variation  in  speed  and 
load;  (2)  A  degree  of  compression  dependent  upon 
the  quantity  of  the  mixture  inhaled;  (3)  A  correct 
proportioning  of  the  mixture  under  all  conditions, 
involving  relatively  weaker  mixtures  for  higher  compres- 
sions and  increasingly  stronger  mixtures  for  lower  com- 
pressions; (4)  A  temperature  of  combustion  exactly 
adapted  to  the  quality  of  fuel  used  and  the  compres- 
sion; (5)  Automatic  control  of  the  internal  temperature 
through  the  admission  of  water  as  part  of  the  fuel 
mixture;  (6)  Thorough  and  uniform  mixture  of  fuel, 
water  and  air  charge  by  mechanical  means  and  without 
the  application  of  additional  heat;  (7)  Automatic 
variation  in  the  time  of  firing  in  response  to  variations 
in  speed  and  power;  (8)  Means  for  changing  the  limits 
of  speed  within  which  all  factors  are  simultaneously 
controlled;  (9)  And  means  for  starting  on  a  limited 
supply  of  volatile  fuel,  all  of  which  factors  are  vital 
to  the  control  of  internal  heat,  the  transformation  of 
heat  into  power  and  power  production  The  adapta- 
bility of  the  system  described  to  the  lower  grade  oils 
is  secured  through  its  providing  a  co-ordination  of  all 
factors  at  all  times,  this  being  considered  necessary 
owing  to  the  more  difficult  vaporization  and  combina- 
tion   of    less    volatile    oils.      The    throttling    governor, 


The  Modern  Gas  Tractor  183 

taking  a  different  quantity  of  fuel  mixture  for  each 
cycle  as  the  load  varies,  naturally  produces  a  varying 
compression  within  the  cylinder.  It  is  well  known 
that  at  higher  compression  leaner  fuel  mixtures  may  be, 
and  should  be  used,  and  vice  versa.  One  great  factor 
in  the  success  of  the  system  is  that  through  the  mechan- 
ism of  the  special  carburetor,  the  proportions  of  fuel, 
air  and  water  are  automatically  varied  in  relation  to 
each  other  as  the  compression  changes.  By  this  means 
the  conditions  within  the  cylinder,  whether  the  engine 
is  run  at  heavy  load  or  light,  are  constant  so  far  as 
they  affect  the  completeness  of  combustion.  Complete 
combustion  eliminates  the  deposit  of  carbon  which 
has  been  regarded  as  an  insurmountable  objection  to 
the  use  of  heavy  fuels,  and  the  unified  automatic  con- 
trol results  in  the  securing  of  splendid  regulation. 

The  automatic  control  of  the  quantity  of  water  is 
an  original  feature  of  the  system,  and  is  advantageous 
for  several  reasons.  In  the  first  place  it  makes  for 
clean  combustion  by  controlling  the  temperature  of 
vaporization  and  combustion  so  that  there  is  practically 
no  cracking  of  the  low-grade  oil  with  its  attendant 
carbon  deposit.  The  water  allows  the  use  of  higher 
compression,  consequently  greater  power  from  the 
same  bore,  stroke  and  speed.  The  effect  of  the 
water  in  producing  a  slower-burning  mixture  is  seen 
in  a  lower  explosion  pressure  and  a  flatter  indicator 
card.  This  results  in  as  high  a  mean  effective  pressure 
as  is  found  in  gasoline  engines  of  similar  proportions, 
without  the  strain  and  instability  produced  by  a  violent 
initial  shock.  There  is  further,  undoubtedly,  a  disso- 
ciation of  water  into  nascent  hydrogen  and  oxygen. 
The  latter,  being  much  more  active  than  the  diluted 
oxygen    of    the    atmosphere,    has    naturally    a    greater 


LS4  The  Modern  Gas  Tractor 

affinity  for  any  free  carbon  that  may  have  been  deposited 
at  the  moment  of  explosion.  The  hydrogen  set  free 
probably  burns  with  the  oxygen  of  the  air  as  the  tem- 
perature falls  toward  the  end  of  the  stroke,  but  it  is 
doubtful  whether  enough  steam  is  thus  formed  to 
exert  any  considerable  expansive  effect  upon  the  piston. 
The  process  does,  however,  effectively  scour  the  cylinder. 
The  explosion  is  converted  into  a  long,  steady  push 
instead  of  a  short,  sharp  blow,  and  the  water  apparently 
gives  an  increase  of  power  of  at  least  15  per  cent  over 
a  similar  engine  without  it. 

The  water  is  not  only  controlled  as  to  amount,  but 
is  brought  into  play  automatically.  As  the  load  increases, 
the  throttle  opens  and  more  air  is  sucked  through  the 
carburetor.  Not  until  about  half  load  is  reached  does 
the  suction  become  strong  enough  to  lift  the  water, 
hence  it  is  not  present  to  hinder  ignition  at  light  loads, 
nor  to  allow  preignition  at  any  time,  being  neither 
too  heavy  for  ignition  at  heavy  loads  nor  too  light 
to   control  the  temperature  of  vaporization. 

Crank  shaft,  cam  shaft,  governor,  magneto,  carbu- 
reter, valves  and  piston  act  as  a  positively  controlled 
unit  in  engines  equipped  with  the  new  system,  hence 
no  one  mechanical  factor  deserves  to  be  set  apart  from 
the  others  in  importance.  However,  the  special  car- 
bureter, which  makes  possible  the  application  of  the 
new  system,  is  of  sufficient  novelty  to  warrant  especial 
attention.  A  fly-ball  governor,  through  a  first-class 
lever  and  a  link  coupling,  operates  a  sliding  brass  valve 
which  is  clearly  shown  in  Fig.  67a.  The  carbureter 
sits  above  the  cylinders,  with  the  short  inlet  manifold 
presenting  little  opportunity  for  the  mixture  to  stratify 
before  it  is  completely  vaporized.  It  contains  constant- 
level    chambers   for   kerosene   and   water,    an   overflow 


The  Modern  Gas  Tractor 


185 


AOJUJT/ne  PLtTt  j 


— Position  of  sliding  valve  at  light  load. 


*—  Longitudinal  section  of  carbureter. 


Fig.  67a. — Views  of  Secor-Higgins  Carburetor,  Used  on  Rumelv 
"Oil  Pull"  Tractors.  Position  of  Sliding  Valve  at  Light 
Load  at  Top,  Side  Sectional  View  of  Device  Showing 
Control  Device,  Air  and  Mixture  Ports,  and  Fuel  and  Water 
Regulation  at  Bottom. 


186  The  Modern  Gas  Tractor 

being  provided  for  each.  It  has  also,  for  starting  pur- 
poses, a  chamber  for  gasoline  which  is  filled  by  hand 
pump.  This  chamber,  which  holds  about  a  pint,  is 
connected  by  a  siphon  with  the  mixing  chamber.  Turn- 
ing the  engine  over  creates  suction  enough  to  draw  upon 
the  contents  of  this  chamber,  but  a  vent  is  provided 
so  that  if  a  start  is  not  made  immediately  the  siphon 
will  not  continue  to  act  and  drain  the  chamber. 

Fig.  67a  shows  the  position  of  the  valve  plate  at  light 
load.  Two  air  inlets  are  then  open,  providing  a  large 
ratio  of  admission  to  outlet  area  and  thus  greatly  re- 
ducing the  relative  vacuum  in  the  mixing  chamber. 
As  the  load  increases,  the  governor  throws  the  sliding 
valve  forward,  increasing  the  area  of  the  outlet  to  the 
cylinder,  increasing  the  air  inlet  in  the  middle,  and 
decreasing  or  entirely  closing  the  air  opening  at  the  right. 
Thus  the  ratio  of  admission  to  outlet  area  decreases, 
the  relative  vacuum  becomes  greater,  and  more  fuel  in 
quantity,  though  not  in  proportion,  is  picked  up  by  the 
incoming  air  and   carried  to  the   cylinder. 

A  sectional  view  from  the  side  shows  the  arrangement 
of  the  kerosene  and  water  needle  valves,  the  overflow, 
etc.  It  will  be  noted  that  the  water  level  is  lower  than 
the  kerosene  level.  The  suction  therefore  is  not  great 
enough,  until  the  engine  reaches  about  half  load,  to 
lift  the  water  to  the  point  (H2)  where  it  can  flow  down 
the  tube  surrounding  the  needle  valve.  From  half  to 
full  load,  the  ratio  of  water  to  fuel  increases  rapidly 
until  the  amounts  of  fuel  and  water  used  are  practically 
equal.  The  carburetor  is  so  designed  that  the  fuel 
needle-valve  (K)  should  be  adjusted  at  the  full-load 
position,  when  the  plate  is  farthest  to  the  right.  This 
order  of  procedure  is  important,  since  at  this  position 
the  adjustable  plate  has  no  effect  upon  the  area  of  the 


The  Modern  Gas  Tractor  187 

air  inlet  openings.  The  adjustment  of  the  air  should 
be  made  at  the  "no-load"  position  and  after  once  made, 
need  never  be  changed,  unless  the  engine  enters  a  very 
different  altitude.  This  adjustable  plate  allows  each 
carburetor  to  be  adjusted  to  the  engine  it  is  to  serve, 
hence  the  slight  variations  in  manufacturing  are  fully 
taken  care  of.  The  sliding  plate  is  the  only  moving 
part  in  the  carburetor,  and  that  is  positively  controlled. 
There  are  no  springs,  floats  or  check  valves.  The 
device  is  simple,  the  parts  are  large  and  there  is  no 
possibility  of  the  device  getting  out  of  order  or  failing 
to  supply  a  correctly  proportioned  mixture  as  long  as 
the  pumps  supplying  fuel  and  water  are  functioning 
properly  and  the  fuel  and  water  containers  are  kept  full. 
Methods  of  Exploding  Charge.— When  the  gas 
engine  was  first  developed  the  compressed  gas  was  ex- 
ploded by  means  of  a  naked  flame  which  was  permitted 
to  communicate  with  the  combustion  chamber  by  means 
of  a  slide  valve  which  moved  at  the  proper  time  to  per- 
mit the  flame  to  ignite  the  gas  back  of  the  piston.  This 
system  of  ignition  was  practical  only  on  the  primitive 
gas  engines  where  the  charge  was  not  compressed  to 
any  degree.  When  it  became  desirable  to  compress 
the  gas  before  firing  it,  the  hot  tube  system  of  ignition 
was  used.  This  method  involved  the  use  of  an  incan- 
descent platinum,  porcelain  or  nickel  tube  in  the  combus- 
tion chamber,  the  tube  or  ignitor  being  kept  in  a  heated 
condition  by  a  flame  burn  ng  in  it.  Another  method 
which  has  been  previously  described,  and  which  is 
illustrated  at  Fig.  61,  depends  upon  the  property  of  gases 
firing  themselves  if  compressed  to  a  sufficient  degree, 
provided  that  a  certain  amount  of  heat  was  stored  in  the 
cylinder  head  to  insure  complete  vaporization  of  the  gas 
and   help   produce   the   proper   kindling  temperature. 


188  The  Modern  Gas  Tractor 

Advantages  of  Electrical  Ignition. — Practically 
all  of  the  gas  engines  in  use  at  the  present  time,  except 
a  few  employed  in  the  oil  fields,  utilize  electrical  ignition 
systems.  In  all  tractor  power  plants  the  compressed 
gas  is  exploded  by  a  minute  electric  arc  or  spark  in 
the  cylinder,  the  current  for  which  is  produced  by  some 
form  of  chemical  or  mechanical  generator  of  electricity. 
The  early  forms  of  ignition  systems  had  a  disadvantage 
in  that  they  were  not  flexible  and  could  be  used  suc- 
cessfully only  on  constant  speed  engines.  None  of 
these  methods  are  practical  in  connection  with  gas 
tractor  power  plants  because  they  do  not  permit  the 
flexible  engine  action  that  is  so  desirable. 

While  electrical  ignition  systems  are  somewhat  more 
complicated  than  the  other  simpler  types,  they  are 
the  most  efficient,  and  as  their  peculiarities  are  now 
generally  understood,  there  is  no  difficulty  in  applying 
them  successfully.  Two  forms  of  electric  ignition 
systems  are  in  general  use,  the  most  popular  being  that 
in  which  a  current  of  electricity  under  high  potential 
or  pressure  is  forced  to  leap  an  air  space  between  the 
points  of  a  spark  plug  which  is  screwed  into  the  cylinder. 
The  other  system,  which  is  used  to  a  limited  extent  on 
gas  tractor  engines,  is  known  as  the  low  tension  system 
because  a  current  of  comparatively  low  voltage  is 
utilized  instead  of  the  high  pressure  current  used  in  the 
more  popular  systems.  Whereas  the  spark  is  produced 
in  the  high  tension  system  by  the  current  heating  up 
the  air  particles  between  the  points  of  the  spark  plug, 
it  is  produced  in  the  combustion  chamber  when  the 
low  tension  method  is  employed  by  moving  electrodes 
which  come  in  contact  with  each  other  and  which 
produce  a  spark  as  they  separate. 

The    essential    elements    of    any    electrical    ignition 


The  Modern  Gas  Tractor  189 

system  are:  First,  a  simple  and  practical  method  of 
current  production;  second,  suitable  timing  apparatus 
to  cause  the  spark  to  occur  at  the  right  point  in  the 
cycle  of  engine  action;  third,  some  form  of  igniter  to 
produce  the  spark  in  the  combustion  chamber;  fourth, 
apparatus  to  transform  the  low  tension  current  obtained 
from  batteries  or  dynamo  to  one  of  greater  value  before 
it  can  produce  a  spark  in  the  cylinder;  and  fifth,  suit- 
able wiring,  switches  and  other  apparatus  to  convey 
the  current  produced  by  the  generator  to  the  auxiliary 
apparatus  and  from  these  to  the  spark  producing  mem- 
ber  in   the    cylinder    head. 

Methods  of  Producing  Current. — There  are  two 
common  means  for  obtaining  the  electrical  current  used 
to  produce  the  spark  in  the  cylinder,  one  of  these  de- 
pending on  a  chemical  action,  the  other  an  electro- 
magnetic action.  The  first  class  includes  the  various 
forms  of  primary  and  secondary  batteries,  while  the 
second  group  includes  the  various  mechanical  ap- 
pliances, such  as  dynamos  and  magnetos. 

Dry  and  Storage  Batteries. — The  simplest  method 
of  current  generation,  and  the  cheapest  as  well,  is  by 
means  of  a  simple  chemical  cell,  generally  known  as 
the  "dry  battery."  These  belong  to  the  primary  cell 
class  because  a  current  of  electricity  is  generated  by 
the  oxidation  of  one  of  the  elements  of  which  the  cell 
is  composed  by  the  electrolyte.  Any  primary  battery 
consists  of  three  main  elements:  First,  a  plate  of  some 
material  which  will  be  acted  on  by  the  electrolyte. 
Second,  an  electrolyte  which  may  be  a  solution  of  a 
salt  or  acid  in  water,  which  will  have  a  chemical  affinity 
for  the  active  element.  Third,  a  neutral  plate  which 
serves  to  collect  the  electricity  produced  by  the  chemical 
combination  of  the  electrolyte  and  active  elements. 


190  The  Modern  (Ias  Tractor 

The  dry  battery  is  so  called  because  the  electrolyte 
is  in  the  form  of  a  paste  instead  of  a  liquid.  The  dry 
cell  consists  of  a  zinc  can  filled  with  electrolyte  and 
a  depolarizing  chemical  in  the  center  of  which  a  carbon 
rod  or  plate  is  placed.  The  function  of  the  depolarizer 
is  to  keep  the  cells  active  for  a  longer  period  than  would 
be  the  case  if  only  a  simple  electrolyte  was  used.  The 
zinc  can  serves  as  a  container  for  the  electrolyte  and 
also  forms  the  active  member.  The  carbon  rod  is  the 
neutral  or  collecting  member.  A  terminal  is  attached 
to  the  zinc  can  and  is  known  as  the  negative,  commonly 
indicated  by  a  minus  sign  thus  ( — )  while  the  terminal 
attached  to  the  carbon  is  known  as  the  positive  con- 
nection (commonly  indicated  by  a  plus  sign  (+).  It 
is  to  these  terminals  that  the  wires  forming  the  external 
circuit  of  the  cell  are  attached,  the  internal  circuit  being 
completed  by  the  electrolyte   and   depolarizer. 

A  single  dry  cell  does  not  have  enough  power  to 
produce  a  spark,  so  a  number  of  these  are  generally 
joined  to  form  a  battery.  The  common  method  of 
connecting  dry  cells  is  in  series;  this  means  that  the 
positive  terminal  of  one  cell  is  always  coupled  to  the 
negative  terminal  of  its  neighbor.  When  cells  are  coupled 
in  this  manner,  the  battery  has  a  voltage  equal  to  that 
of  one  cell  times  the  number  of  cells  so  joined.  For 
instance,  four  dry  cells  would  have  a  potential  or  cur- 
rent pressure  of  six  volts,  as  one  dry  cell  has  a  pressure 
of  one  and  one-half  volts.  The  amount  of  current 
produced  by  the  batteries  is  measured  in  amperes  and 
the  battery  capacity  will  depend  upon  the  size  of  the 
active  element  and  the  strength  of  the  electrolyte. 
The  ordinary  No.  6  dry  cell  which  is  six  inches  high 
by  two  and  one-half  inches  in  diameter  will  indicate 
a  current  strength   of  about  twenty  amperes.      When 


The  Modern  (Jas  Tractor  191 

cells  are  joined  in  series  the  amperage  of  the  set  is  equal 
to  that  of  but  one  cell.  If  it  is  desired  to  obtain  greater 
amperage,  the  cells  are  joined  in  multiple,  which  means 
that  all  terminals  of  similar  polarity  are  joined  together. 
A  battery  of  four  dry  cells  connected  in  this  manner 
would  deliver  a  current  of  about  eighty  amperes. 

When  dry  batteries  are  used  for  ignition  purposes, 
they  are  generally  coupled  together  in  a  series-multiple 
connection  to  obtain  the  proper  voltage  and  current 
strength.  The  dry  battery  has  a  number  of  advantages, 
chief  among  which  are  its  cheapness,  ease  of  installa- 
tion, compactness  and  simplicity.  It  has  the  dis- 
advantage of  being  limited  in  capacity  and  not  suited 
for  continuous  work,  which  it  shares  with  all  other 
forms  of  primary  battery.  When  dry  cells  are  exhausted 
there  is  no  method  of  renewing  them  to  efficiency  and 
they  must  be  replaced.  This  is  not  a  serious  factor, 
however,  as  an  entire  new  set  of  six  cells  will  cost  but 
$1.50. 

The  storage  battery  is  a  chemical  current  producer 
that  is  capable  of  being  recharged  when  it  is  exhausted 
by  passing  a  current  of  electricity  through  it  in  a  reverse 
direction  to  that  of  the  current  given  out.  Storage 
batteries  are  composed  of  elements  of  practically  the 
same  material  and  can  only  become  active  when  a 
current  of  electricity  is  passed  through  them.  The 
materials  generally  used  are  grids  of  lead  filled  with 
a  paste  composed  of  lead  oxide.  When  the  current  of 
electricity  passes  through  these  plates,  they  become 
enough  different  in  nature  so  that  a  difference  of  elec- 
trical condition  exists  between  them,  and  when  the  cell 
is  fully  charged,  a  current  may  be  drawn  from  it  in  just 
the  same  way  as  from  a  primary  battery. 

Storage  batteries  have  the  advantage  that  they  may 


1!>2  The  Modern  Gas  Tractor 

be  used  for  continuous  current  production,  and  as  they 
may  be  recharged  when  exhausted,  it  is  not  necessary 
to  replace  them  with  new  members  when  they  will  no 
longer  produce  current.  The  storage  battery  is  called 
a  "secondary  cell"  because  it  can  only  give  out  energy 
after  a  current  of  electricity  has  passed  through  it,  where- 
as a  primary  battery  in  good  condition  will  produce 
electricity  as  soon  as  it  is  completed.  The  storage 
battery  uses  an  electrolyte  composed  of  dilute  sulphuric 
acid  and  water,  while  a  dry  battery  uses  an  alkaline 
electrolyte  composed  largely  of  sal-ammoniac  and 
chloride  of  zinc. 

The  average  form  of  storage  battery  used  for  igni- 
tion purposes  is  really  composed  of  three  cells,  which 
are  placed  in  a  common  carrying  case  of  wood  or  hard 
rubber.  The  connection  between  the  cells  is  made 
by  plates  of  lead  which  are  burned  to  the  elements, 
leaving  but  two  terminals  free,  one  of  which  is  a  nega- 
tive member  while  the  other  leads  from  the  positive 
plates.  To  prevent  spilling  of  the  electrolyte  the  top 
of  the  cell  or  battery  is  sealed  with  a  hard  rubber  plate 
over  which  is  poured  a  pitch  and  rosin  compound. 
The  electrolyte  is  renewed  through  a  small  vent  in  each 
cell  which  is  covered  by  a  removable  hard  rubber  cap. 
These  vents  also  allow  for  the  escape  of  the  gases  evolved 
when  the  cell  is  being  charged  or  when  it  is  delivering 
a  current  of  electricity.  The  average  ignition  battery 
has  a  capacity  of  60  to  80  ampere  hours  and  a  current 
pressure  of  about  6.6  volts  when  fully  charged. 

Functions  of  Induction  Coil. — The  current  ob- 
tained from  a  dry  or  storage  battery  is  not  sufficiently 
powerful  to  leap  the  gap  that  exists  between  the  points 
of  a  spark  plug  utilized  in  the  high  tension  ignition 
system.     This  space  offers  a  resistance  to  the  passage 


The  Modern  Gas  Tractor  193 

of  the  current  that  requires  a  pressure  of  several  thousand 
volts  to  overcome,  and  as  the  ordinary  ignition  battery 
produces  but  six  volts  it  will  be  apparent  that  unless 
the  current  strength  is  increased  it  could  not  over- 
come the  resistance  of  the  air  gap  between  the  spark 
plug  points.  A  simple  device  known  as  an  "induction 
coil"  is  employed  to  transform  the  low  tension  battery 
current  to  a  current  of  sufficient  voltage  to  jump  the 
air  gap  at  the  plug.  The  current  from  the  battery  is 
first  passed  through  the  primary  coil,  which  is  composed 
of  several  layers  of  coarse  wire  wound  around  a  core  of 
lengths  of  soft  iron  wire  to  form  an  electro-magnet. 
Another  coil  composed  of  a  large  number  of  turns  of 
finer  wire  is  wound  over  the  primary  coil.  When  a 
current  of  electricity  of  low  voltage  passes  through 
the  primary  coil,  a  current  of  high  electro-motive 
force  is  delivered  from  the  terminals  of  the  secondary 
winding. 

The  induction  coil  is  usually  provided  with  a  device 
known  as  a  "vibrator,"  which  is  an  automatic  circuit 
breaker  actuated  by  the  magnetism  of  the  core.  Every 
time  the  circuit  is  made  and  broken  at  the  vibrator 
contact  points  an  electrical  impulse  is  induced  at  the 
secondary  winding,  and  the  more  rapid  the  vibration, 
the  greater  the  number  of  impulses  in  the  secondary 
current.  A  simple  coil,  such  as  used  for  single  cylinder 
ignition,  is  shown  at  Fig.  68.  As  will  be  seen,  three  ter- 
minals are  provided  on  the  coil  exterior,  one  leading 
to  the  battery,  one  to  the  commutator,  and  the  re- 
maining one  to  the  spark  plug.  The  vibrator  spring 
A  carries  one  of  the  contact  points  and  the  knurled 
head  aduj sting  screw  B  carries  the  other.  The  ampli- 
tude of  vibration  is  varied  by  moving  the  adjusting 
screw    B   or   by   increasing   or   decreasing   the   strength 


194  The  Modern  Gas  Tractor 

of  the  vibrator  spring.  An  induction  coil  for  use  with 
a  multiple  cylinder  engine  is  composed  of  a  number  of 
simple  coils  fastened  together  in  a  common  case  and 
having  enough  terminals  to  make  the  proper  connec- 
tions in  the  outer  circuit,  as  will  be  described  in  proper 
sequence.  When  the  vibrator  is  in  operation  it  moves 
so  rapidly  that  it  makes  a  buzz  like  that  of  some  fast 
flying  insect  and  when  properly  adjusted  it  may  even 
give  a  definite  musical  note.     If  the  vibrator  action  is 


Fig.  68. — Induction   Coil  Used   in   Connection   With   Batteries 
to  Produce  Electric   Spark  in   Gas   Engine   Cylinder. 

not  rapid  the  amount  of  secondary  current  produced 
will  not  be  as  great  nor  will  it  have  as  high  voltage 
because  the  current  output  is  dependent  not  only  upon 
the  number  of  impulses  flowing  through  the  primary 
coil  but  also  upon  the  rapidity  of  the  contacts  at  the 
vibrator. 

Producing  Spark  in  Cylinders. — The  two  common 


The  Modern  Gas  Tractor 


195 


appliances  for  producing  an  electric  spark  in  the  com- 
bustion chamber  are  shown  at  Fig.  69.  That  at  A 
is  a  low  tension  igniter  plate  having  a  movable  electrode. 
One  of  the  spark  points  is  carried  in  a  fixed  member 
or  anvil  which  is  shown  detached  so  the  construction 
may  be  understood  and  which  is  installed  in  and  insu- 
lated from  the  main  body  of  the  igniter  plate.  The 
movable  member,  which  is  actuated  by  a  bell  crank, 
carries  the  other  contact  point  and  is  normally  in  con- 
tact  with   the   anvil.      When   it   is   desired   to   produce 


Termina, 


Spnrk  Point 


Anuil  Insulator 


Spark  Points 


Fig.  69. — Devices  for  Producing  Spark  in  Engine  Cylinder- 
A — Low  Tension  Igniter  Plate.  B — High  Tension  Spark 
Plug. 

a  spark  the  hammer  is  pulled  away  from  the  anvil  by 
some  mechanical  means,  usually  a  tappet  rod  operated 
by  a  plunger  and  cam  in  just  the  same  manner  as  a 
valve  is  lifted.  At  the  instant  of  breaking  contact  a 
hot  spark  takes  place  between  the  points  and  this 
explodes  the  mixture.  There  are  other  forms  of  low 
tension    igniters    but    the    type    described    is    the    most 


196  The  Modern  Gas  Tractor 

common,    and   has   demonstrated   that   it   is   the   most 
practical. 

The  obvious  disadvantage  of  this  construction  is 
that  the  moving  member  in  the  hot  combustion  chamber 
may  become  fouled  with  carbon,  or  the  points  may 
become  burnt  and  covered  with  scale  to  such  an  extent 
that  the  electrical  connection  made  when  they  touch 
will  be  very  poor.  Then,  as  is  true  of  all  moving  mech- 
anism, the  factor  of  deterioration  enters  into  considera- 
tion. Considerable  difficulty  is  experienced  in  keeping 
the  joint  around  the  hammer  spindle  tight  and  the 
result  is  that  as  soon  as  this  wears  the  action  of  the 
igniter  becomes  erratic  and  mixture  troubles  may  result 
due  to  dilution  of  the  charge  by  air  which  leaks  into 
the  combustion  chamber  through  the  worn  hammer 
bearing. 

The  factor  of  wear  is  an  important  one  in  that  it  also 
affects  the  timing  and  on  a  multiple  cylinder  engine 
it  may  be  found  difficult  to  secure  proper  firing  of  all 
the  cylinders.  Those  in  which  the  mechanism  is  worn 
most  will  not  fire  at  the  same  relative  time  in  the  cycle 
of  operations  as  will  the  other  members  that  are  not 
worn  so  much.  The  result  of  the  explosions  not  fol- 
lowing in  regular  sequence  is  irregular  engine  operation 
and  lack  of  smoothness  in  power  delivery.  Low  tension 
igniters  are  entirely  practical  on  simple  forms  of  low 
speed  engines  but  are  not  suited  to  higher  speed  mul- 
tiple cylinder  power  plants. 

One  of  the  marked  advantages  of  the  low  tension  igni- 
tion system  is  that  it  will  produce  a  spark  having  a 
greater  heat  value  than  will  the  ordinary  high  tension 
system.  This  advantage  is  of  some  moment  when 
using  the  lower  grade  fuels  that  will  not  ignite  as  readily 
as  will  a  gasoline  vapor.     It  is  claimed  by  those  who 


The  Modern  (Ias  Tractor  197 

favor  the  low  tension  system  of  ignition  that  it  will 
ignite  a  greater  range  of  mixtures  than  the  thinner  and 
less  hot  high  tension  spark. 

The  simplicity  of  the  conventional  form  of  spark 
plug  used  with  the  various  high  tension  ignition  systems 
is  clearl^v  outlined  at  Fig.  69-B.  Not  only  is  the  device 
more  simple  than  the  low  tension  igniter  plate  but 
it  has  no  moving  parts.  It  will  be  seen  that  the  main 
member  of  the  plug  is  a  steel  shell,  which  is  provided 
with  a  thread  at  the  bottom  by  which  the  plug  is  screwed 
into  the  cylinder.  One  of  the  electrodes  is  attached 
to  this  shell  as  indicated.  The  other  electrode  is  in  the 
form  of  a  light  rod  or  wire,  carried  through  the  center 
of  some  insulating  medium  which  in  this  case  is  a  por- 
celain bushing.  This  bushing  is  capped  with  a  terminal 
nut  by  which  the  device  is  connected  into  the  outer 
circuit.  The  porcelain  insulator  is  held  against  a  pack- 
ing or  gasket  by  a  threaded  gland  which  screws  into 
the  upper  portion  of  a  plug  body. 

Spark  plug  construction  varies  widely,  but  all  operate 
on  exactly  the  same  principle.  The  arrangement  of 
spark  points  may  be  different  and  mica  or  glass  may 
be  used  instead  of  porcelain  insulation,  but  the  action 
remains  the  same.  As  will  be  evident,  the  only  parts 
of  the  plug  that  are  exposed  to  the  hot  gases  are  the 
spark  points  and  the  lower  portion  of  the  porcelain 
insulating  bushing.  There  is  practically  no  part  that 
will  cause  trouble  or  that  will  wear  in  service  and  the 
device  needs  but  little  attention  after  it  is  once  in- 
stalled. Even  if  it  should  fail  to  work  because  of  a  cracked 
insulator  or  a  defective  spark  point  the  entire  device 
may  be  renewed  for  fifty  or  seventy-five  cents  and,  as 
is  true  of  the  dry  cell  battery,  it  is  often  cheaper  to 
renew  them  than  to  attempt  to  make  repairs. 


108  The  Modern  Gas  Tractor 

In  most  forms  of  spark  plugs  the  porcelain  is  easy  to 
remove  and  if  a  spare  insulator  is  at  hand  it  may  be 
readily  substituted  for  the  imperfect  ones  by  any- 
body who  is  able  to  handle  a  wrench.  There  is  no 
more  or  less  complicated  mechanism  to  time  and  if 
the  insulator  is  kept  free  from  carbon  and  soot  and  the 
spark  points  separated  by  the  proper  gap,  there  is 
no  opportunity  for  irregular  ignition.  As  the  spark 
plug  may  be  screwed  tightly  into  the  cylinder  it  is  easy 
to  obtain  a  gas  tight  joint,  and  the  mixture  troubles 
and  hissing  incidental  to  worn  igniter  plates  are  not 
present. 

Mechanical  Generator  Advantages. — Taking  elec- 
tricity from  either  a  dry  or  storage  battery  is  com- 
parable to  drawing  a  liquid  from  a  reservoir  filled  with 
a  certain  definite  supply.  As  the  demands  upon  the 
reservoir  increase,  its  capacity  and  the  amount  of  liquid 
it  contains  become  less  in  direct  proportion.  Batteries 
cannot  maintain  a  constant  output  of  electricity  for  an 
indefinite  period  and  their  strength  is  reduced  according 
to  the  amount  of  service  they  give.  A  mechanical 
generator  of  electricity  produces  current  without  any 
actual  deterioration  or  depreciation  of  chemicals  and 
plates,  as  is  true  of  a  battery.  There  is  some  wear 
present  in  a  mechanical  generator  but  this  is  so  small 
compared  to  the  amount  of  service  it  will  give  that  its 
effect  is  practically  negligible  as  regards  current  out- 
put. 

A  simple  analogy  that  will  enable  one  to  appreciate 
the  merits  of  the  mechanical  generator  may  be  made 
with  a  pump  system  of  drawing  a  liquid  from  a  prac- 
tically inexhaustible  reservoir.  As  long  as  the  pump 
is  turned  it  will  supply  liquid.  The  same  thing  is  true 
of    a    mechanical    generator    of    electricity    which    will 


The  Modern  Gas  Tractor  l!»!i 

supply  current  as  long  as  the  rotating  parts  are  turned. 
With  batteries,  when  the  engine  speed  increases  and  the 
demands  upon  them  become  greater  the  current  strength 
decreases  at  a  time  it  should  be  strong.  With  a  mechani- 
cal generator  of  electricity  the  current  output  increases 
as  the  speed,  and  as  these  devices  are  usually  driven 
directly  from  the  engine,  when  this  member  demands 
more  electricity  the  mechanical  generator  will  supply 
it  automatically  because  it  is  being  driven  faster. 

Types  of  Magnetos. — There  are  two  forms  of  mecha- 
nical generators  commonly  used  and  the  principle  of 
action  is  somewhat  the  same.  They  differ  widely, 
however,  in  construction  and  method  of  application. 
The  first  forms  used  to  replace  batteries  were  pat- 
terned after  the  dynamo  electric  machines  used  for 
supplying  current  for  electric  lighting  and  other  indus- 
trial purposes.  The  dynamo  was  later  simplified  by 
the  elimination  of  one  set  of  windings  and  it  was  made 
lighter  and  more  efficient.  This  form  of  mechani- 
cal generator  is  called  a  "magneto"  because  perman- 
ent magnets  are  utilized  instead  of  wire  wound  or  elec- 
tro magnets.  The  dynamo  form  of  generator  is  used 
where  currents  of  considerable  value  are  needed,  while 
the  magneto  is  generally  applied  for  ignition  purposes. 
Another  advantage  of  the  magneto  is  that  it  may  be 
made  so  it  will  contain  a  complete  ignition  system  in 
itself,  whereas  when  a  dynamo  is  employed  practi- 
cally the  same  conditions  obtain  as  though  batteries 
were  used.  The  dynamo  merely  replaces  the  chemi- 
cal current  producer. 

A  mechanical  generator  of  electricity  produces  cur- 
rent by  an  induction  action.  It  is  a  known  fact  that 
if  an  insulated  wire  is  wound  around  a  bar  of  iron  or 
steel  and  a  current  of  electricity  is  passed  through  it, 


200 


The  Modern  Gas  Tractor 


the  metal  will  become  magnetized,  i.  e.,  it  possesses 
the  property  of  attracting  other  pieces  of  iron  or  steel 
to  it.  As  a  current  of  electricity  flowing  through  a 
wire  wound  around  a  bar  of  steel  will  make  a  magnet 
of  it,  if  a  magnet  is  inserted  into  an  inactive  coil  of 
wire  it  will  generate  a  current  of  electricity  by  a  reversal 
of  the  phenomena  first  mentioned.  In  other  words,  a 
current  of  electricity  will  be  produced  in  a  conductor 
by  a  magnet  if  either  of  these  is  moved  in  such  a  way 


Fig.  70. — Oscillating    Armature    Low    Tension    Magneto    and 
Integral    Igniter   Plate   a   Complete    Ignition   System. 

that  the  field  of  magnetic  influence  is  traversed  or  cut 
by  the  wire.  In  a  dynamo  or  magneto  a  number  of 
coils  of  wire  are  mounted  on  a  revolving  member,  termed 
the  armature,  which  is  placed  between  the  pole  pieces 
of  the  energizing  or  field  magnet.  The  faster  the  arma- 
ture rotates,  the  more  rapidly  do  the  armature  windings 
pass  through  the  magnetic  field  and  the  greater  the  num- 
ber of  electrical  impulses  produced  because  one  of  these 


The  Modern  Gas  Tractor  201 

is  created  every  time  a  loop  of  wire  passes  through  the 
magnetic  field. 

Oscillating  Armature  Forms. — The  armature  of  a 
magneto  is  not  always  a  revolving  member  except 
when  this  device  is  used  to  produce  a  continuous  flow 
of  current.  In  some  ignition  systems  a  single  electric 
impulse  is  all  that  is  needed  to  produce  the  spark.  A 
number  of  low  tension  magnetos  are  made  on  the  oscil- 
lating armature  principle.  One  of  these  is  clearly  shown 
at  Fig.  70.  Instead  of  the  armature  being  a  revolving 
member  it  is  an  oscillating  member  and  does  not  make 
a  complete  revolution.  In  the  device  shown  the  armature 
is  replaced  by  an  inductor  member  which  carries  no 
wire  and  which  oscillates  freely  between  the  pole  pieces 
of  the  magnets.  The  form  depicted  is  really  a  unit  with 
the  igniter  plug  and  is  adapted  to  be  bolted  to  the  side 
of  the  cylinder  in  such  a  way  that  while  the  igniter 
points  project  into  the  combustion  chamber,  the  device 
is  in  a  position  close  to  the  cylinder  head  where  it  may 
be  readily  operated  by  means  of  a  push-rod  and  trip 
from  the  engine  cam  shaft. 

The  device  is  so  arranged  that  when  a  spark  is 
desired  between  the  ignitor  points,  the  inductor  is  given 
a  quick  movement  which  produces  a  flow  of  magnetic 
energy  through  the  windings.  At  the  same  instant  that 
the  flow  of  electricity  takes  place  through  the  coils, 
the  ignitor  points  are  separated  and  a  spark  is  produced 
in  the  cylinder.  The  action  of  a  device  of  this  character 
is  automatic,  and  each  time  that  the  magneto  push- 
rod  trips  the  inductor  the  points  of  the  ignitor  separate 
and  a  spark  is  obtained  to  ignite  the  compressed  gas. 

It  is  apparent  that  this  method  of  current  genera- 
tion will  take  but  very  little  power  from  the  engine  and 
that   there   can  be  no   depreciation   that   will   tend  to 


202 


The  Modern  Gas  Tractor 


diminish  the  amount  of  current  at  a  time  that  the  engine 
needs  a  hot,  fat  spark.  This  device  forms  a  complete 
ignition  system  and  is  suitable  for  practically  all  sta- 
tionary engines  of  the  single  cylinder  or  two  cylinder 
patterns.  It  would  not  be  advisable  to  furnish  this 
form  of  magneto  for  more  than  two  cylinders  because 
a  separate  device  is  needed  for  each  cylinder  and  the 
mechanical  complication  incidental  to  the  use  of  four 
of  these  devices  with  the  trip  rods,  etc.,  would  not  be 
desirable. 


/sll  ira^F 

r              "^^mr^^ - 

^MAGNETS 

ARMATURE 
(ENCASEDA 

COMMUTATOR^ 
(ENCASED)    t 

FRICTION  DRIVE 
PULLEY, 

bBBI 

BRUSHES  lit 
(ENCASED)   \      x> 

illflll^ 

jji     GOVERNOR 

'brush  holder  (encased) 

■ 

Fig.  71. — Revolving  Armature  Magneto  Delivering  Low  Ten- 
sion Current.  Used  in  Connection  With  Induction  Coil, 
Timer  and  Spark  Plug  to  Form  Complete  Ignition  System. 

Type  With  Revolving  Armature. — The  revolving 
armature  type  of  magneto  is  the  form  that  is  generally 
used  for  supplying   current   whenever   a   constant   flow 


The  Modern  Gas  Tractor  203 

is  desired.  When  a  device  of  this  nature  is  intended 
to  replace  batteries  it  is  of  the  low  tension  direct  current 
form,  as  shown  at  Fig.  71.  The  magnetic  field  is  produced 
by  a  pair  of  permanent  magnets  attached  to  pole  pieces 
between  which  the  armature  revolves.  The  electricity 
produced  in  the  coils  of  wire  in  the  armature  is  collected 
by  means  of  two  brushes  which  form  the  terminals  cor- 
responding to  the  positive  and  negative  poles  of  a 
battery.  As  a  device  of  this  character  is  intended  to 
be  driven  at  a  constant  speed,  an  automatic  governor 
is  usually  provided  which  becomes  inoperative  when 
the  safe  speed  of  magneto  rotation  is  exceeded. 

The  form  shown  is  intended  to  be  driven  by  means 
of  a  friction  drive  pulley  bearing  against  the  flywheel. 
This  pulley  drives  the  armature  by  frictional  contact 
between  the  governor  arms  and  the  outer  tapered  face 
of  the  drive  pulley.  This  member  is  faced  with  fiber 
or  leather  where  it  bears  against  the  engine  flywheel 
in  order  to  secure  greater  frictional  adhesion.  The 
governor  arms  are  carried  by  a  fitting  which  is  attached 
to  the  armature  shaft,  while  the  friction  drive  pulley 
is  free  to  rotate  on  the  armature  shaft  except  at  those 
times  when  the  governor  arms  are  in  contact  with  its 
face.  When  the  speed  increases  to  a  point  where  the 
governor  arms  will  fly  out  because  the  centrifugal  force 
is  greater  than  the  tension  of  the  coil  springs  holding 
them  in  contact  with  the  pulley,  the  drive  is  interrupted, 
and  the  friction  drive  pulley  turns  at  one  speed  while 
the  armature,  which  now  revolves  only  by  its  own 
momentum,  tends  to  slow  down.  The  armature  speed 
finally  slackens  to  a  point  where  centrifugal  force  is 
not  strong  enough  to  keep  the  weighted  governor  arms 
out  of  contact  with  the  friction  drive  pulley.  The  ten- 
sion springs  then  act  and  the  armature  is  driven  from 


204 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  205 

the  friction  pulley  until  the  safe  speed  is  again  exceeded 
at  which  time  the  driving  connection  will  be  auto- 
matically broken  again.  The  device  shown  is  wired  into 
the  circuit  just  as  the  set  of  batteries  would  be  and 
an  induction  coil  and  timer  will  be  needed  to  complete 
the  ignition  system. 

High  Tension  Device. — The  high  tension  magneto 
is  the  form  that  is  generally  used  in  automobile  igni- 
tion systems  and  its  popularity  is  increasing  among  gas 
tractor  manufacturers  as  well.  The  advantages  of  the 
true  high  tension  magneto  are  that  it  comprises  in 
one  device  all  the  elements  of  the  current  generating 
and  intensifying  devices  and  all  that  is  needed  in  con- 
nection with  a  high  tension  magneto  are  the  spark  plugs 
and  the  wires  by  which  they  are  connected  to  the  instru- 
ment. A  high  tension  magneto  for  a  four  cylinder  engine 
is  but  very  little  more  complicated  than  one  used  on 
a  two  cylinder  power  plant.  The  only  difference  is  in 
the  number  of  contacts  in  the  distributor  and  the 
speed  at  which  the  device  is  driven. 

A  typical  high  tension  magneto  utilized  in  connection 
with  a  four  cylinder  engine  is  outlined  at  Fig.  72  and 
all  the  parts  are  clearly  shown.  The  armature  is  a 
two  pole  type  having  an  approximately  H  section  and 
it  is  wound  with  two  coils  of  wire.  One  of  these  is  a 
comparatively  coarse  one  corresponding  to  the  primary 
winding  of  an  induction  coil,  while  the  other  is  a  fine 
winding  having  many  turns  that  correspond  to  the 
secondary  coil.  The  armature  shaft  is  mounted  on  ball 
bearings  to  insure  easy  rotation.  The  magnetic  field 
is  produced  by  means  of  three  pairs  of  horseshoe  mag- 
nets which  are  attached  to  pole  pieces  which  form  the 
armature  tunnel.  Mounted  on  and  turning  with  the 
armature  is  a  condenser  which  is  placed  in  shunt  con- 


206  The  Modern  Gas  Tractor 

nection  with  the  contact  points  in  the  magneto  breaker 
box.  The  armature  is  driven  by  means  of  positive 
chain  or  gear  drive  and  it  is  timed  in  such  a  way  that 
the  contact  points  of  the  magneto  contact  breaker 
separate  only  when  a  spark  is  desired  in  the  engine. 

On  a  four  cylinder  motor  the  magneto  is  driven  at 
crankshaft  speed,  the  contact  breaker  cams  being  ar- 
ranged in  such  a  manner  that  the  contact  points  sepa- 
rate twice  during  each  revolution  of  the  armature.  Every 
time  the  contact  points  are  separated  a  current  of  elec- 
tricity leaves  the  armature  by  means  of  a  high  tension 
brush  which  bears  on  the  insulated  contact  ring  carried 
at  one  end  of  the  armature  shaft  and  is  led  to  a  dis- 
tributing brush  at  the  center  of  the  secondary  current 
distributing  member.  The  spark  plugs  are  attached  to 
wires  which  lead  to  the  segments  in  the  distributor, 
there  being  one  segment  for  each  spark  plug.  The 
distributor  shaft  is  revolved  at  half  armature  speed  by 
means  of  gears  and  the  revolving  contact  brush  makes 
contact  with  one  of  the  segments  each  time  that  the 
spark  points  separate,  so  that  the  current  of  electricity 
is  directed  to  the  plug  which  is  in  the  cylinder  about 
to  fire.  It  will  be  seen  that  this  device  includes  the 
current  generating  and  commutating  means  as  well 
as  the  timing  mechanism. 

A  magneto  for  a  two  cylinder  engine  would  have  but 
two  distributor  segments  and  would  be  driven  at  cam- 
shaft speed  or  half  that  of  the  crank  shaft.  A  magneto 
for  a  three  cylinder  engine  would  have  the  segments 
spaced  120  degrees  apart  in  the  distributor  and  would 
be  driven  at  three-quarters  crankshaft  speed.  On  a 
six  cylinder  motor  the  magneto  would  be  driven  at  one 
and  one-half  times  crankshaft  speed  and  there  would 
be  six  segments  in  the  distributor,   spaced  60  degrees 


The  Modern  Gas  Tractor  207 

apart.  In  the  four  cylinder  form  shown  the  distributor 
segments  are  arranged  on  quarters  of  the  circle  or 
90  degrees  apart. 

The  contact  breaker,  which  corresponds  to  the  timer 
of  a  battery  ignition  system,  consists  of  a  fixed  member 
which  carries  one  of  the  platinum  contact  screws  while 
the  movable  bell  crank  lever  carries  the  other  platinum 
contact.  The  condenser  is  used  to  absorb  a  surplus 
current  which  is  due  to  self  induction  between  the 
various  windings  of  wire  and  to  prevent  the  excess  cur- 
rent so  generated  from  producing  a  spark  that  would 
tend  to  burn  the  contact  points  as  they  separate.  The 
safety  spark  gap  is  interposed  between  the  high  tension 
brush  and  the  ground  in  such  a  way  that  any  excess 
current  that  might  injure  the  windings  if  it  was  allowed 
to  go  through  the  instrument  in  the  regular  manner 
will  be  allowed  to  flow  to  the  ground  without  passing 
through  the  external  circuit.  This  device  performs  the 
same  function  for  the  magneto  as  a  safety  valve  does 
for  a  steam  boiler,  in  that  it  provides  a  means  of  escape 
for  excess  pressure  that  might  injure  the  device  if  no 
means  were  provided  for  its  disposal  other  than  the 
regular  channels  of  distribution.  The  action  of  the 
magneto  ignition  system  will  be  described  more  in 
detail  when  considering  the  operation  of  complete 
ignition  groups. 

Low  Tension  Ignition  Systems. — The  practical 
application  of  a  low  tension  ignition  system  to  a  four 
cylinder  engine  is  clearly  outlined  at  Fig.  73.  Two 
sources  of  current  are  provided,  one  a  mechanical 
generator  while  the  other  is  a  battery  of  ten  dry  cells 
in  series.  A  two-way  switch  is  provided  so  either  battery 
or  magneto  may  be  used  as  desired.  As  a  general  rule 
the  magneto  is  used  for  regular  ignition  and  the  battery 


208 


The  Modern  Gas  Tractor 


is  called  upon  to  deliver  current  only  for  starting  and 
in  event  of  emergencies  in  which  the  mechanical  genera- 
tor might  get  out  of  order.  The  four  igniters  are  con- 
nected to  a  common  conductor  or  bus  bar  which  is 
insulated  from  the  metal  portions  of  the  engine  and 
which  is  connected  to  the  top  of  the  switch  lever  by 
means  of  a  single  wire.  A  wire  runs  from  the  magneto 
collector  brush  to  one  side  of  the  switch,  while  a  conduc- 
tor from  the  spark  coil,  which  is  in  series  with  the  bat- 
teries, connects  to  the  other  side  of  the  switch.     One  of 


Battery 


-    f  Co/7 


Mag/ieto 


Battery 


Fig.  73. — Typical  Four  Cylinder  Low  Tension  Ignition  System. 

the  battery  terminals  is  attached  to  the  frame  or  base 
of  the  engine  and  one  of  the  magneto  leads  is  also 
grounded. 

It  will  be  evident  that  when  the  switch  lever  is  in 
central  position,  as  shown,  neither  magneto  nor  battery 
and  coil  set  is  in  service  and  that  there  can  be  no 
spark  in  the  cylinder.  If  the  switch  lever  is  placed  on 
one  contact  button  the  battery  ignition  system  can  be 


The  Modern  Gas  Tractor 


209 


used,  and  if  it  is  moved  to  the  other  contact  button, 
the  current  for  ignition  will  be  obtained  from  the  me- 
chanical generator. 

Simple  Battery  Ignition  Methods. — The  compon- 
ents of  a  simple  battery  ignition  system  are  shown  in 
outline  form  at  Fig.  74,  the  ignition  system  being  that 
for  a  single  cylinder  engine.  As  is  true  of  the  low  tension 
system  previously  described,  two  methods  of  current 
generation  are  provided,    a  two-way  switch  being  in- 


Fig.  74. — Simple    Ignition    System    for    One    Cylinder    Engine 
Using  Battery  and  Magneto. 

stalled  in  the  circuit  of  both  magneto  and  battery 
leads.  The  switch  F  is  attached  to  the  outside  of  the 
battery  box,  which  carries  the  dry  cells  B  and  the 
induction  coil  M.  The  secondary  terminal  of  the  induc- 
tion coil  is  attached  to  spark  plug  E  which  is  placed  in 
the  combustion  chamber  of  the  cylinder.  One  terminal 
of  the  induction  coil  M  is  grounded  on  the  engine,  as 


21(1 


The  Modern  (!as  Tractor 


at  Q.  The  central  terminal  of  the  switch  F  goes  to 
the  insulated  terminal  of  the  timer  D.  One  of  the  leads 
of  the  battery  D  is  attached  to  one  of  the  contact  but- 
tons of  the  switch  while  the  other  goes  to  the  remaining 
primary  terminal  of  the  induction  coil. 

The  magneto  H   is  similarly  connected,   one  of  the 


Fig.  75. — Two    Cylinder   Battery    and    Coil    Ignition    System. 

leads  going  to  one  side  of  the  switch  while  the  other 
goes  to  the  primary  terminals  of  the  coil  M.  Either 
magneto  or  battery  may  be  used,  depending  uoon  the 
position  of  the  switch  lever.  When  the  switch  is  thrown 
in  contact  the  circuit  is  still  broken  until  such  time  that 


The  Modern  <1as  Tractok  211 

the  timer  D  makes  contact  between  the  two  members. 
When  this  occurs  the  current  from  the  battery  or  mag- 
neto, depending  upon  which  is  thrown  in  circuit  at  the 
switch,  will  pass  through  the  primary  coil  of  the  induction 
coil  M.  This  produces  a  secondary  current  of  sufficient 
magnitude  to  produce  a  spark  between  the  points  of 
the  spark  plug  E.  As  soon  as  the  timer  breaks  contact 
the  primary  circuit  is  interrupted  and  the  spark  between 
the  points  of  the  spark  plug  ceases.  In  actual  practice 
contact  at  the  timer  D  is  established  only  for  an  instant 
every  two  revolutions  of  the  crankshaft  and  the  parts 
are  arranged  and  timed  in  such  a  manner  that  the 
spark  takes  place  only  when  the  piston  has  reached  the 
end  of  its  compression  stroke  and  the  compressed 
charge  of  gas  is  ready  to  be  exploded. 

The  ignition  system  for  a  two  cylinder  opposed  engine 
is  outlined  in  diagram  form  at  Fig.  75.  In  this  the  only 
source  of  current  supply  is  a  set  of  six  dry  cells,  wired 
in  series.  The  switch  is  a  two-point  type  and  either  a 
battery  or  magneto  may  be  coupled  to  the  free  terminal 
just  the  same  as  in  the  simple  ignition  system  pre- 
viously described.  The  spark  coil,  which  is  the  trans- 
former form  used  in  the  high  tension  ignition  system, 
is  composed  of  two  distinct  units  wired  together  in  a 
common  case  leaving  five  exposed  terminals.  Those 
located  at  the  top  of  the  coil  are  joined  to  the  primary 
circuit,  one  of  the  three  that  is  marked  "battery"  going 
to  the  central  terminal  of  the  switch  while  the  other 
two  that  are  marked  '"commutator"  (com.)  are  attached 
to  the  insulated  terminals  of  the  two-point  timer.  The 
two  terminals  at  the  side  of  the  coil  are  high  tension 
leads,  one  for  each  coil  unit,  and  are  joined  to  the  spark 
plugs  by  the  usual  form  of  conductor.  With  this  system 
each  unit  of  the  coil  fires  one  of  the  cylinders  and  the 


212 


The  Modern  Gas  Tractor 


two-point  timer  serves  to  establish  the  circuit  required 
to  produce  a  spark  at  the  proper  time.  As  the  explo- 
sions occur  in  regular  order  the  contact  points  of  the 
timer,  which  is  driven  at  half  the  engine  speed,  are 
spaced  on  the  halves  of  the  circle  or  180  degrees  apart. 
A  typical  four  cylinder  ignition  system  in  which  batter- 
ies alone  are  employed  to  generate  electricity  is  clearly 


High  Tension  Wires 


Induction  Coil 
Switch 


Primary  Circuit 


Storage  Buttery 


Fig.  76. — Four    Cylinder    Ignition    System    Utilizing    Battery 
Current. 

outlined  at  Fig.  76.  The  commutator,  or  timer  in  this 
case,  is  a  four  point  type,  having  four  insulated  con- 
tacts and  one  revolving  member  which  establishes  the 
proper  connection  with  each  of  the  insulated  members 
as  it  revolves.  The  timer  is  driven  at  half  of  the  crank- 
shaft speed,  and  as  two  explosions  occur  each  revolution 
the  insulated  timer  segments  are  spaced  ninety  degrees 
apart.    The  induction  coil  employed  is  a  four  unit  type. 


The  Modern  Gas  Tractor  l'1:'» 

The  four  individual  members  are  carried  in  a  common 
case  and  wired  so  a  minimum  number  of  terminals  to 
which  wires  must  be  attached  are  on  the  outside  of  the 
case.  The  switch,  which  is  a  two  point  type,  is  mounted 
on  the  face  of  the  induction  coil  box.  Two  sets  of 
batteries  are  provided,  one  of  the  dry  cell  form,  the  other 
a  six  volt  storage  battery.  The  negative  terminals 
of  both  storage  battery  and  dry  battery  are  joined  by 
a  common  wire  which  is  grounded  on  the  engine  base. 
The  positive  terminals  of  each  battery  are  led  to  the 
two  primary  terminals  immediately  under  the  switch 
at  the  bottom  of  the  coil.  Four  large,  well  insulated 
wires  lead  from  the  bottom  of  the  coil  to  the  cylin- 
ders, while  the  four  primary  conductors  join  the  in- 
sulated contact  members  of  the  timer  and  the  pri- 
mary  terminals   at   the  top  of  the  coil. 

The  central  revolving  member  of  the  timer  is  grounded 
so  that  the  effect,  as  far  as  the  circuit  is  concerned,  is 
just  as  though  the  negative  wire  from  both  sets  of  bat- 
teries were  connected  directly  with  it.  When  the  switch 
lever  is  placed  on  the  button  at  the  right,  the  storage 
battery  is  thrown  in  the  circuit  and  the  ignition  current 
for  regular  running  is  obtained.  When  the  lever  is 
switched  over  to  the  other  side  the  dry  batteries,  which 
are  usually  reserved  for  emergency  duty,  are  put  into 
action.  The  operation  of  this  system  is  identical  with 
that  of  the  simple  one  cylinder  ignition  system,  pre- 
viously considered,  excepting  that  the  various  units 
of  the  coil  are  brought  into  the  circuit  progressively  in 
the  proper  firing  order.  The  four  cylinder  engine  illus- 
trated has  a  firing  order  of  1,  2,  4,  3.  The  front  cylinder 
fires  first  during  the  first  half  of  the  first  revolution  of 
the  crankshaft,  while  the  second  cylinder,  which  is  the 
one  immediately  back  of  it,  fires  during  the  second  half 


214 


The  Modern  Gas  Tractor 


of  the  first  revolution  of  the  crankshaft.  The  fourth 
cylinder  delivers  a  power  stroke  during  the  first  half 
of  the  second  revolution,  this  being  followed  by  the 
third  cylinder,  which  delivers  power  to  the  crankshaft 
the  second  half  of   the  second  revolution. 

Action  of  Magneto   Ignition  Systems. — In  order 
to  simplify  the  explanation  of  the  action  of  a  typical 


High  Tension  Wire 
to  Distributor 


Segment 


Distributor  Brush  - 


Secondary  Winding 
Primary  Winding- 
Stationary  Windin 


Win  to 
Intulaiad  Contact 


Platinum  Tipped  Screw 


Fig.  77. — Diagram  Explaning  Action  of  Four  Cylinder  Magneto 
Ignition   System    Used   on    "Big   4-30"    Gas   Tractor. 

high  tension  magneto,  the  various  essential  parts  that 
are  in  circuit  are  shown  at  Fig.  77.  The  magneto  shown 
has  a  revolving  inductor  member  instead  of  the  conven- 
tional form  of  armature  and  a  stationary  double  coil 
mounted  in  the  center  of  the  device  in  such  a  way  that 
the  magnetic  influence  from  the  field  magnet  is  directed 
through  the  coil  at  the  time  that  a  spark  is  desired  in 


The  Modern  Gas  Tractor 


215 


w 

J 

< / 

216 


The  Modern  Gas  Tractor 


the  cylinder.  As  will  be  observed,  one  of  the  leads  from 
the  stationary  primary  winding  goes  to  the  ground  while 
the  other  is  led  to  the  insulated  contact  point  of  the 
contact  breaker.  The  condenser  is  interposed  in  the 
circuit  so  that  it  is  in  shunt  or  parallel  connection  with 


Fig.  79. — Illustration  Showing  Advance  and  Retard  Positions 
of  K.  W.  Magneto  Breaker  Box. 

the  contact  points.  As  the  two  members  comprising 
the  condenser  are  insulated  from  each  other  the  primary 
current  cannot  flow  through  this  device.  One  of  the 
high  tension  leads  from  the  secondary  winding  is  directed 


The  Modern  Gas  Tractor  217 

to  the  ground  while  the  other  goes  to  the  revolving 
distributor  brush  of  the  distributing  device.  Four 
wires  lead  from  the  distributor  to  the  various  spark 
plugs  of  the  engine. 

When  the  points  in  the  contact  breaker  are  separated 
by  the  cam  point  a  current  of  electricity  is  induced  in 
the  stationary  winding  because  the  inductor  is  at  such 
a  position  between  the  pole  pieces  that  a  maximum 
current  of  electricity  is  being  produced.  The  high  ten- 
sion current  is  distributed  to  the  spark  plug  in  the  cylin- 
der about  to  ignite,  the  spark  plugs  being  brought  into 
action  progressively  as  the  magneto  distributor  brush 
establishes  contact  with  the  insulated  segments  to  which 
the  plug  wires  are  attached.  The  application  of  a  typical 
true  high  tension  magneto  to  a  four  cylinder  gas  tractor 
power  plant  is  outlined  at  Fig.  78  and  attention  is 
directed  to  the  simplicity  of  the  external  wiring. 

Timing  the  Spark. — The  contact  breaker  of  either 
a  magneto  or  battery  ignition  system  should  be  arranged 
in  some  manner  so  that  the  time  of  sparking  may  be 
varied.  In  starting  the  engine  by  hand  it  is  imperative 
that  the  spark  be  retarded,  which  means  that  it  should 
occur  later  than  the  correct  ignition  point  and  only 
after  the  piston  has  started  to  go  down  again  after  it 
has  reached  the  top  of  the  compression  stroke.  When 
the  spark  takes  place  under  these  conditions  the  piston 
is  always  driven  in  the  right  direction  and  the  engine 
cannot  back  fire.  If  the  engine  were  started  with  the 
spark  advanced  the  explosion  would  take  place  before 
the  piston  had  reached  the  end  of  its  compression  stroke 
and  it  would  be  driven  back  in  a  direction  opposite  to 
that  in  which  it  should  normally  revolve.  This  will 
tend  to  knock  the  starting  crank  or  flywheel  out  of 
the  operators  grasp  and  may  result  in  a  permanent  injury 


218  The  .Modern  Gas  Tractor 

to  the  wrist  or  arm  if  this  is  not  removed  out  of  the 
path  of  the  incorrectly  rotating  starting  handle. 

While  a  late  spark  is  desirable  for  starting  and  run- 
ning an  engine  at  low  speed  it  is  necessary  to  advance 
the  spark  when  it  is  desired  to  operate  the  motor  at 
a  higher  speed.  To  do  this  the  timer  case  is  usually 
rocked  so  the  contact  will  be  broken  sooner  between 
the  points  of  the  magneto  contact  breaker  or  estab- 
lished earlier  in  a  timer  for  a  battery  ignition  system. 
The  positions  of  a  magneto  contact  breaker  when  in 
advance  and  retard  positions  are  clearly  shown  at  Fig. 
79.  It  will  be  seen  that  to  obtain  an  advance  spark 
the  timer  case  is  rocked  so  that  the  roller  on  the  movable 
timer  lever  is  brought  into  contact  with  the  point  of 
the  cam  sooner.  In  other  words,  to  advance  the  time 
of  the  spark,  the  timer  case  is  rocked  in  a  direction 
opposite  to  that  of  rotation  of  the  circuit  breaking  cam, 
whereas  to  retard  the  spark  the  contact  breaker  casing 
is  oscillated  in  the  same  direction  as  that  of  cam  rota- 
tion so  the  points  of  the  contact  breaker  would  be  sepa- 
rated after  the  piston  has  started  to  go  down  on  its 
explosion  stroke. 


CHAPTER  VI. 

COOLING  AND  LUBRICATING  THE  POWER  PLANT. 

Reason  for  Cooling  Engine — Thermo-syphon  System — Forced 
Circulation  Method — Oil  Cooling  Features — Parts  of  Cool- 
ing System — The  Pump — The  Cooling  Fan — The  Radia- 
tor— Why  Engines  are  Oiled— Different  Lubricating  Med- 
iums— Simple  Gravity  Oil  Cup  Method — Mechanical  Oiling 
Systems — Constant  Level  Splash  Systems. 

Reason  for  Cooling  Engine. — It  is  apparent  that 
power  is  produced  in  an  internal-combustion  engine  by  a 
series  of  explosions  in  the  cylinder.  As  the  temperature 
of  the  explosion  is  over  2,000  deg.  Fahr.  in  some  cases, 
the  rapid  combustion  and  continued  series  of  explosions 
would  soon  heat  up  the  metal  parts  of  the  combustion 
chamber  to  such  a  point  that  they  would  show  color 
unless  cooling  means  were  provided.  Under  these  condi- 
tions it  would  be  impossible  to  lubricate  the  cylinder 
because  even  the  best  quality  of  lubricating  oil  would 
be  burnt.  The  piston  would  expand  sufficiently  to  seize 
in  the  cylinder  and  the  valves  would  warp  so  that  they 
could  no  longer  hold  compression.  Premature  ignition 
of  the  charge  would  probably  take  place  long  before  the 
engine  was  put  out  of  commission  by  the  distortion  of 
the  parts. 

The  fact  that  the  ratio  of  engine  efficiency  is  dependent 
upon  the  amount  of  useful  work  delivered  by  the  heat 
generated  from  the  explosion  makes  it  important  that 

219 


212(1 


Tin:  Modern  Gas  Tractor 


the  jackets  be  cooled  to  a  point  where  the  cylinder  will 
not  be  robbed  of  too  much  heat.  The  losses  through  the 
water  jacket  of  the  average  gas-tractor  power  plant  are 
over  50  per  cent  of  the  total  fuel  efficiency.  While  it  is 
very  important  that  the  engine  should  not  get  too  hot, 

it  is  equally  de- 
sirable that  it 
is  not  cooled 
too  much.  The 
object  of  cylin- 
der cooling  is, 
therefore,  to 
keep  the  heat 
of  the  cylinder 
metal  below 
the  danger 
point  but 
a  t  the  same 
time  keep  the 
engine  hot 
enough  to  ob- 
tain maximum 
power  from  the 
gas  burnt. 

Two  general 
systems  of  cyl- 
inder  cooling 
are  in  general 
use  on  farm  en- 
gines, though 
the  simpler  air-cooled  types  are  never  found  on  gas 
tractors  of  regular  manufacture,  because  air  cooling  is 
not  considered  practical  for  heavy-duty  motors  of  the 
bore  and  stroke  used  as  gas  tractor  power  plants.  Water 


Fig.  80. — Part  Sectional  View  of  Water 
Jacketed  Motor  Cylinder. 


The  Modern-  (i.\s  Tractor  l'l'1 

cooling  is  the  most  popular  method  in  all  fields  of 
endeavor  in  which  the  gasoline  engine  has  been  applied 
successfully  with  the  exception  of  the  motor  cycle  and 
aeroplane. 

When  a  liquid  is  employed  for  cooling  it  is  circulated 
through  jackets  which  surround  the  cylinder  castings, 
and  when  the  excess  heat  is  absorbed,  the  hot  liquid 
(usually  water  but  sometimes  oil)  is  led  to  a  cooler  where 
the  heat  is  abstracted  from  it  by  means  of  air  currents. 
The  cooled  liquid  is  then  taken  from  the  cooler  and  again 
circulated  around  the  cylinders  of  the  motor.  The 
sectional  view  of  a  typical  cylinder  at  Fig.  80  shows  the 
liberal  space  provided  for  water  circulation. 

Two  methods  of  keeping  the  cooling  liquid  in  motion 
are  used.  The  simplest  system  is  to  utilize  a  natural 
principle  that  a  hot  liquid  being  lighter  than  a  cold 
liquid  will  tend  to  rise  to  the  top  of  the  cylinder  when  it 
becomes  heated,  while  cool  water,  which  is  heavier,  takes 
its  place  at  the  bottom  of  the  water  jacket.  The  slightly 
more  complicated  system  generally  favored  is  to  use  a 
positive  circulating  pump  of  some  form  which  is  driven 
by  the  engine  to  keep  the  cooling  liquid  in  circulation. 

Thermo  Syphon  System. — Some  eminent  tractor 
designers  contend  that  the  rapid  circulation  of  liquid 
obtained  by  means  of  a  pump  may  cool  the  cylinders 
too  much  and  the  temperature  of  the  engine  may  be 
reduced  to  a  point  where  its  efficiency  will  be  somewhat 
lower  than  if  the  engine  were  allowed  to  run  hotter. 
For  this  reason  many  designers,  especially  in  the  auto- 
mobile field,  use  the  natural  method  of  water  circulation. 
The  cooling  liquid  is  applied  to  the  cylinder  jackets 
below  the  boiling  point  and  the  water  issues  from  the 
top  of  the  jacket  after  it  has  absorbed  enough  heat  to 
raise  it  just  about  to  the  boiling  point.    The  simplicity  of 


222 


Thk  Modern  Gas  Tractor 


the  thermo  syphon  system  of  cooling  is  clearly  outlined 
at  Fig.  81.  With  this  system  of  cooling  it  is  necessary 
to  use  more  liquid  than  with  pump  circulated  systems 
and  the  water  jackets  of  the  cylinders,  as  well  as  the 
water  spaces  in  the  radiator  and  the  water  inlet  and  dis- 
charge manifolds,  must  have  greater  capacity  and  be  free 


Fig.  81.— Action    of    Simple    Thermo-Syphon    Cooling   System 
Outlined. 

from  sharp  corners  that  might  impede  the  flow  of  liquid. 
The  direction  of  flow  of  the  currents  of  water  are  clearly 
depicted  and  there  should  be  no  difficulty  in  understand- 
ing the  action  of  this  form  of  cooling  system. 

The    Forced    Circulation    Method. — A   system   of 
cooling  in  which  a  pump  is  depended  on  to  promote  cir- 


The  Modern  Gas  Tractor 


culation  of  water  is  shown  at  Fig.  82.  The  radiator  is 
generally  carried  at  the  front  end  of  the  tractor  frame 
and  serves  as  a  combined  water  tank  and  cooler  in  most 
cases.  It  is  usually  composed  of  upper  and  lower  water 
tanks,  joined  together  by  a  series  of  pipes,  which  may  be 
round  and  provided  with  a  number  of  corrugated  flanges 
to  radiate  the  heat,  or  which  may  be  flat  in  order  to  have 
the  water  pass  through  in  thin  sheets  and  cool  more 


COLD    WATER 


Fig.  82. — Forced  Water  Circulation  Method  of  Cooling  Engine 
Cylinders. 

easily.  The  cold  water  which  settles  at  the  bottom  of 
the  cooler  is  drawn  from  the  lower  part  of  the  radiator 
by  a  gear-driven  pump  and  is  forced  through  a  manifold 
to  the  water  jackets  surrounding  the  exhaust  valve 
chamber  of  the  cylinder.  As  the  water  becomes  heated 
it  passes  out  of  the  top  of  the  water  jacket  into  the 


224  The  Modern  Gas  Tractor 

upper  portion  of  the  radiator,  but  as  a  general  rule  the 
rate  of  circulation  is  dependent  upon  the  power  of  the 
pump  rather  than  the  degree  of  temperature  of  the  water. 
On  account  of  the  more  rapid  flow  of  liquid,  the  radiator 
and  piping  may  be  of  less  capacity  than  when  the  simple 
thermo-syphon  is  employed. 

Oil=cooIing  Features. — Some  tractor  manufactur- 
ers use  oil  as  a  cooling  medium  instead  of  water  because 
this  material  is  claimed  to  be  more  satisfactory  in  cold 
weather.  Water  will  freeze  unless  it  is  mixed  with  some 
anti-freezing  solution  such  as  wood  alcohol,  glycerine 
mixtures  and  calcium  chloride  solutions.  Many  tractor 
operators  do  not  care  to  use  anti-freezing  compounds 
either  because  of  expense  or  on  account  of  a  chemical 
action  and  salt  deposit  which  is  present  when  the  cheaper 
alkaline  solutions  are  used.  If  pure  water  is  used  in  the 
cylinder  jacket  as  a  cooling  medium,  it  must  be  drained 
from  the  cylinder  and  cooler  as  soon  as  the  engine  is 
stopped  if  the  temperature  is  below  32  deg.  Fahr. 

The  Hart-Parr  oil-cooling  system  is  outlined  at  Fig. 
83.  This  is  claimed  to  have  been  in  successful  operation 
for  a  number  of  years  without  any  question  ever  having 
been  raised  regarding  its  efficiency.  The  system  is  very 
similar  in  action  to  that  of  the  conventional  forced  cir- 
culation water-cooling  group,  except  that  the  radiator 
and  cylinder  jackets  are  filled  with  a  special  cooling  oil 
which  takes  the  place  of  the  usual  water  supply.  As  the 
oil  never  boils  and  as  there  is  no  waste  because  of  evapo- 
ration, the  original  oil  supply  furnished  with  the  tractor 
should  last  as  long  as  the  engine  itself.  Any  loss  due  to 
leakage  may  be  cheaply  renewed. 

The  radiator  is  constructed  of  numerous  thin  corru- 
gated sections,  with  a  conical  hood  and  short  stack  at  the 
top.    The  exhaust  is  piped  into  the  hood  and  the  exhaust 


Flo.  83.— Seotional  View  of  Hart-Part  Horizontal  Power  riant  Showing  Oil  Cooling  Method. 


The  Modern  Gas  Tractor  225 

gases  are  discharged  upward  from  the  exhaust  pipe 
through  numerous  holes,  this  causing  a  powerful  draft 
through  the  cooler  because  of  an  ejector  action  and  also 
acting  as  a  muffler  for  the  exhaust  by  softening  the  sharp 
reports  so  that  they  are  not  annoying.  The  cylinder  is 
kept  sufficiently  cool  for  successful  operation  of  the  en- 
gine in  even  the  hottest  weather,  or  when  worked  under 
full  load  continuously  for  any  number  of  consecutive 
hours.  The  circulating  pump  is  mounted  at  the  top  of 
the  engine  and  is  driven  by  positive  means.  The  method 
by  which  the  various  pipes  are  joined  to  the  pump, 
water  jacket  and  cooler,  and  the  construction  of  all  parts 
of  the  power  plant,  as  well  as  the  cooling  system,  are  so 
clearly  shown  that  further  description  is  unnecessary. 

Parts  of  Cooling  Systems. — It  will  be  seen  that  the 
parts  of  the  simplest  cooling  system  used  in  practical 
work  are  not  very  complicated,  consisting  simply  of  a 
container  for  water,  which  may  or  may  not  combine  the 
functions  of  a  cooler  as  well,  and  suitable  piping  to  con- 
nect the  water  jackets  of  the  motor  to  the  water  tank. 
With  a  pump  circulation  system  this  and  its  driving 
means  are  practically  the  only  additions  to  the  simpler 
natural  circulation  method. 

The  Pump. — Pumps  used  in  connection  with  water- 
cooling  systems  are  of  two  general  forms,  those  in  which 
the  water  is  circulated  by  revolving  gears  or  paddle 
wheel  and  the  other  and  more  positive  form  which  is  of 
the  plunger  type.  The  rotary  pumps  are  more  popular 
than  the  reciprocating  members  because  there  is  no  neces- 
sity for  forcing  the  water  along  under  pressure  to  any 
great  extent.  The  simpler  forms  which  promote  circulation 
by  keeping  the  water  in  motion  are  all  that  are  needed. 
The  pump  is  usually  driven  by  positive  means,  oftentimes 
by  gearing  direct  from  the  motor  crank  shaft  or  cam  shaft. 


226 


The  Modern  Gas  Tractor 


The  principal  parts  of  a  simple  centrifugal  pump  are 
clearly  outlined  at  Fig.  84.  The  impeller  or  paddle- 
wheel  member  is  secured  to  the  center  of  the  shaft  which 
is  supported  at  each  end  by  bearings  in  the  members 
comprising  the  pump  casing.  This  is  made  in  two  parts, 
usually  divided  vertically  along  the  center  line  of  the 
impeller  wheel.    The  halves  of  the  pump  casing  are  faced 


IMPELLER 


DISCMARGE 


INTAKE 


Fig.  84. — Simple   Form   of   Centrifugal   Pump   for   Circulating 
Cooling  Liquid. 

off  so  that  the  joint  matches  well  and  a  water-tight  point 
of  junction  is  insured  by  a  packing  between  the  halves 
held  positively  in  place  by  means  of  through  bolts  hold- 
ing the  two  halves  of  the  casing  together.  To  obtain 
proper  service  from  a  centrifugal  pump  the  vanes  of  the 
impeller  wheel  should  be  a  fair  fit  in  the  pump  casing. 
Other  forms  of  rotary  pumps  in  which  a  pair  of  gears  or 
an  eccentrically  placed  revolving  element  are  incorpor- 
ated are  also  used,  but  not  so  widely  as  the  simple  form 
of  centrifugal  pump  described. 


Tin:  Modern  (Ias  Tractor 


21*7 


The  Cooling  Fan. — As  gas  tractors  are  compara- 
tively slow-moving  machines,  one  cannot  depend  on  the 
circulation  of  air  through  the  radiator  tubes  by  the 
natural  draft,  as  is  the  case  in  many  automobiles  travel- 
ing at  high  speed.  This  condition  is  met  in  two  ways, 
the  simplest  expedient  being  to  provide  a  water  con- 
tainer of  large  capacity,  having  a  large  amount  of  radi- 


DR!Vir\!G  PULLEY 

\ 


PUMP 


Fig.  85. — Cooling    Fan    Necessary    Unless    Large    Volume    of 
Water  is  Carried. 

ating  surface.  In  the  better  designed  tractors,  the  lack 
of  natural  draft  is  compensated  for  by  using  a  positively 
driven  four  or  six-blade  fan  back  of  the  radiator,  the 
blades  being  inclined  at  such  an  angle  that  air  is  drawn 
in  through  the  radiator  spaces. 

These  fans,  one  of  which  is  shown  at  Fig.  85,  are  driven 


228  The  Modern  Gas  Tractor 

by  leather  belts  running  over  flanged  pullies,  as  a  rule, 
though  sometimes  more  positive  gear-driving  means  are 
employed.  When  a  belt  is  used  for  driving  the  fan  some 
method  of  adjustment  by  which  the  belt  tension  may  be 
maintained  to  the  proper  degree  to  insure  positive  drive 
is  provided.  With  gearing  this  is  not  necessary,  though 
it  is  advisable  to  provide  some  form  of  friction  member 
between  the  fan  hub  and  the  positive  driving  means  to 
prevent  throwing  off  a  fan  blade  should  the  engine  action 
become  "jerky"  and  fan  drive  irregular. 

When  a  fan  is  employed  the  positive  circulation  of  air 
insured  by  its  use  enables  the  tractor  designer  to  obtain 
adequate  cooling  with  much  less  water  than  would  be 
needed  if  the  fan  were  not  used.  The  argument  offered 
against  its  use  that  it  introduces  an  item  of  complication 
in  the  tractor  mechanism  is  true  to  a  limited  extent  but 
the  construction  of  the  fan  is  so  simple  and  the  means 
employed  in  driving  it  so  apparent  that  it  is  not  likely 
to  cause  any  trouble  to  even  the  inexperienced  gas  trac- 
tioneer. 

The  Radiator. — The  simplest  form  of  radiator  is 
shown  at  Fig.  86.  This  is  really  a  combined  water  tank 
and  cooler.  The  lower  portion  is  a  galvanized  iron  tank 
which  carries  a  couple  of  headers  or  supporting  brackets 
at  each  end  to  which  corrugated  pieces  of  sheet  metal 
resembling  to  some  extent  the  metal  face  of  a  washboard 
are  attached.  At  the  top  of  these  corrugated,  inclined 
members  are  the  water  discharge  pipes  from  the  top  of 
the  water  jacket  of  the  engine.  Under  the  influence  of 
the  pump  the  cold  water  pumped  into  the  bottom  of  the 
water  jacket  is  constantly  forcing  the  hot  water  through 
the  pipes  of  the  cooling  system  to  the  perforated  pipes  at 
the  top  of  the  cooler.  The  large  number  of  small  holes 
insures  that  the  same  number  of  streams  of  water  will  be 


The  Modern  Gas  Tractor 


229 


WATER    SPRAY    PIPE 
\       COOLING  WA 


X 


/" 


?}Mclei\ 

/  \Timron } 


WATER TANK 


Fig.  86. — Simple  Combined  Cooler  and  Water  Container. 

discharged  which  trickle  down  the  corrugated  surface  of 
sheet  metal.  As  this  is  cooled  by  exposing  a  large  sur- 
face to  the  air  and  as  the  water  is  divided,  in  a  series  of 
very  thin  streams  from  which  the  heat  is  readily  ab- 
stracted when  it  reaches  the  bottom  or  tank  portion,  it 
has  become  cooled  enough  so  it  can  be  forced  back  into 
the  water  jacket  of  the  engine  again. 

A  much  more  efficient  type  of  cooler  is  shown  at  Fig. 


230 


The  Modern  Gas  Tractor 


86-A.  This  is  composed  of  an  upper  and  lower  header, 
which  are  joined  together  by  a  number  of  readily  detach- 
able units,  each  comprising  four  pipes  around  which  a 
large  number  of  light  sheet  metal  flanges  are  attached  to 


Fig.  864.— Radiator  Used  on   Holt  Tractors  Has  Detachable 
Cooling  Sections. 


The  Modern  Gas  Tractor  231 

increase  the  effective  area  of  metal  exposed  to  the  air. 
This  type  of  radiator  has  the  advantage  of  permitting 
the  ready  removal  of  any  one  of  the  sections  should  it 
become  damaged  in  any  way  without  putting  the  cooler 
out  of  commission.  All  that  is  necessary  is  to  stop  up 
the  holes  by  means  of  a  plate  and  packing.  As  the  water 
in  descending  from  the  top  container  to  the  lower  por- 
tion of  the  radiator  must  pass  through  a  large  number  of 
tubes  and  as  a  positive  air  current  is  induced  by  means  of 
a  power-driven  fan,  placed  in  back  of  them,  very  satis- 
factory cooling  is  obtained  without  the  necessity  of 
carrying  a  large  amount  of  water,  as  is  needed  with  the 
simpler  types  of  radiator  shown  at  Fig.  86. 

Other  radiators  are  composed  of  rectangular  section 
tanks  or  cylindrical  containers  through  which  a  large 
number  of  light  steel  or  copper  tubes  pass  in  just  the 
same  manner  as  the  tubes  of  a  fire  tube  boiler.  The 
cooling  air  currents  are  drawn  through  the  tubes  to  cool 
the  mass  of  water  surrounding  them,  which  is  the  reverse 
to  the  process  employed  in  a  boiler  where  hot  gases  are 
passed  through  the  tubes  to  heat  the  water.  When  this 
form  of  radiator  is  used  it  is  necessary  to  supply  a  fan 
to  produce  a  positive  air  draft  and  insure  adequate  cool- 
ing without  the  use  of  excessively  large  water  capacity. 

Why  Engines  Are  Oiled. — All  bearing  surfaces,  no 
matter  how  smooth  they  appear  to  be  to  the  naked  eye, 
have  minute  projections,  and  when  examined  under  a 
microscope  the  surface  of  even  a  finely  finished  bearing 
appears  rough.  If  bearings  were  run  without  oil,  the 
projections  on  the  shaft  and  on  the  bushing  or  box  in 
which  the  shaft  revolves  would  tend  to  interlock  and  a 
great  amount  of  friction  would  result.  This  would  mean 
that  much  of  the  power  developed  by  the  engine  would 
be  utilized  in  overcoming  friction.    Without  some  means 


2'A2  The  Modern  Gas  Tractor 

of  minimizing  this  loss  considerable  heat  would  be  gen- 
erated if  the  bearings  were  run  dry  and  the  result  would 
be  that  the  overheated  bearings  would  soon  depreciate 
and  would  give  signs  of  distress  long  before  they  failed 
by  becoming  firmly  burned  together. 

The  reason  that  a  lubricant  is  supplied  to  bearing 
points  will  be  readily  understood  if  one  considers  that 
the  close-fitting  surfaces  of  the  shaft  and  bushings  are 
separated  by  means  of  an  elastic  substance  which  not 
only  fills  up  the  minute  depressions,  thus  acting  as  a 
cushion,  but  which  absorbs  the  heat  generated  by  fric- 
tion as  well.  In  properly  lubricated  bearings  the  oil 
takes  all  the  wear  that  would  otherwise  come  on  the 
metallic  bearings.  The  grade  of  oil  and  amount  to  use 
depend  entirely  on  the  bearing  points  where  it  is  to  be 
applied.  An  oil  that  would  be  entirely  suitable  for 
lubricating  the  interior  surfaces  of  the  gas-engine  cylin- 
der would  not  be  suitable  for  bearings  in  some  cases  if 
these  were  subjected  to  heavy  pressures.  At  the  other 
hand  the  semi-fluid  oil  or  grease  which  cushions  the 
teeth  of  the  driving  gearing  so  well  could  not  be  used  in 
the  cylinders  of  the  engine. 

When  used  for  gas-engine  lubrication  an  oil  must  be 
capable  of  withstanding  considerable  heat  in  order  that 
it  will  not  be  evaporated  or  decomposed  by  the  hot 
metal  of  the  cylinder.  The  oil  used  for  cylinders  or 
bearings  should  have  a  low  cold  test,  i.  e.,  it  should  not 
thicken  up  at  low  temperatures  so  that  it  will  not  flow 
freely.  All  authorities  contend  that  lubricants  must  be 
free  from  acid  which  will  corrode  the  metal  surfaces  to 
which  the  oil  is  applied.  A  lubricant  must  have  suffi- 
cient body  to  prevent  metallic  contact  of  the  parts  to 
which  it  is  applied,  and  between  which  it  is  depended 
upon  to  maintain  a  resilient  film.     It  should  not  have 


The  Modern  Gas  Tractor  233 

too  high  a  body  or  too  much  viscosity  because  a  lubricant 
that  is  too  thick  will  have  considerable  friction  in  itself 
and  will  not  flow  readily  between  bearing  surfaces. 

If  the  lubricant  is  to  be  used  in  slow-moving,  high- 
capacity  bearings,  such  as  those  of  a  rear  axle,  or  in 
gearing  where  great  cushioning  qualities  are  desired  in 
addition  to  positive  lubrication,  it  must  have  a  heavy 
body  and  the  semi-solid  greases  are  the  best  materials 
to  use  for  this  purpose.  The  grease  or  oil  should  also 
be  free  from  injurious  adulterants  of  either  vegetable 
or  animal  origin,  because  these  invariably  contain  fatty 
acids  that  will  decompose  and  attack  metal  surfaces  or 
gums  which  will  coagulate  or  oxidize  by  exposure  to  air 
and  retard  the  action  of  the  bearings.  The  best  lubri- 
cants for  tractor  use  are  derived  from  a  crude  petroleum 
base  with  the  exception  of  commonly  employed  graphite 
which  is  a  form  of  pure  carbon  that  is  a  good  lubricating 
medium. 

Different  Lubricating  Mediums. — Oils  of  organic 
origin,  such  as  those  obtained  from  animal  fats  or  veget- 
able substances,  will  absorb  oxygen  from  the  atmosphere 
which  may  cause  them  to  become  rancid.  As  a  rule 
these  oils  have  a  very  poor  cold  test  because  they  solidify 
at  comparatively  high  temperatures.  Their  flashing 
point  and  fire  test  are  also  so  low  that  they  are  not  suit- 
able at  points  where  considerable  heat  exists,  such  as  the 
interior  of  a  gas  engine.  The  only  oil  that  is  used  to  any 
extent  in  lubricating  gas  engines  that  is  not  derived  from 
a  petroleum  base  is  castor  oil  which  is  obtained  by  press- 
ing the  seeds  of  the  castor  plant.  This  has  been  used  on 
high-speed  racing  automobile  engines  and  on  aeroplane 
power  plants,  where  it  is  practically  pushed  right  up 
past  the  piston  and  out  of  the  combustion  chamber  with 
the  exhaust  gases  so  that  fresh  oil  must  be  supplied  all 


234  The  Modern  Gas  Tractor 

the  time  to  replace  that  ejected  from  the  engine.  Obvi- 
ously this  method  of  oiling  would  not  be  considered 
economical  and  would  not  be  suitable  on  either  business 
or  pleasure  automobiles  or  gas  tractors. 

Among  the  solid  substances  that  have  been  used  for 
lubrication  to  some  extent  may  be  mentioned  tallow, 
wrhich  is  obtained  from  the  fat  of  certain  animals,  such 
as  cattle  and  sheep;  graphite,  which  is  a  natural  product, 
and  soapstone,  which  is  also  of  mineral  derivation.  Tal- 
low is  usually  employed  as  a  filler  for  some  of  the  greases 
used  in  slow-speed  bearings  or  in  transmission  gearing 
but  should  never  be  utilized  at  points  where  it  will  be 
exposed  to  much  heat.  Graphite  is  obtained  commer- 
cially in  two  forms,  the  best  known  being  flake  graphite, 
where  it  exists  in  the  form  of  small  scales  or  minute 
sheets,  and  the  deflocculated  form,  where  the  graphite 
has  been  ground  or  otherwise  divided  into  a  dust.  It  is 
usually  mixed  with  oil  of  high  viscosity  and  used  in  con- 
nection with  lubrication  of  running  gear  parts,  though  it 
has  been  mixed  with  cylinder  oil  and  applied  to  engine 
lubrication  with  some  degree  of  success.  Graphite  is 
not  affected  by  heat  or  cold,  acids  or  alkali,  and  has  a 
strong  attraction  for  metal  surfaces.  It  remains  in  place 
better  than  an  oil  and  as  it  mixes  readily  with  oils  and 
greases  their  efficiency  for  many  applications  is  increased 
by  its  use. 

The  oil  that  is  to  be  used  in  the  gasoline  engine  must 
be  of  high  quality  and  for  that  reason  the  best  grades 
are  distilled  in  a  vacuum  so  the  light  distillates  will  be 
separated  at  a  much  lower  temperature  than  ordinary 
distilling  practice  permits.  When  distilled  at  the  lower 
heat  the  petroleum  is  not  so  apt  to  decompose  and  de- 
posit free  carbon.  A  suitable  lubricant  for  gas-engine 
cylinders  has  a  vaporizing  point  at  about  200  deg.  Fahr., 


The  Modern  Gas  Tractor 


235 


a  flash  point  of  430  deg.  Fahr.,  and  a  fire  test  of  about 
600  deg.  Fahr.  Cylinder  oil  is  one  lubricant  that  must 
be  purchased  very  carefully.  A  point  to  remember  is 
that  the  best  quality  oils,  which  are  the  most  efficient, 
can  only  be  obtained  by  paying  well  for  them.  The  few 
cents  saved  in  using  a  cheap  oil  is  not  of  much  moment 
when  compared  to  the  repair  bill  that  may  accrue  from 
its  use.  The  cheap  oil  will  not  only  deposit  carbon  very 
freely  in  the  cylinder  heads  but  is  liable  to  gum  up  the 
piston  rings  and  valves  and  detract  much  from  the 
smooth  operation  and  power  capacity  of  the  motor. 
Bearings  lubricated  with  it  will  also  have  more  friction  and 
consume  more  power  than  when  good  oils  are  employed. 


Grauity' 
Oil  Cup 


Oil  Groove 


Fig.  87. — Oiling  by    Gravity    Feed    Oil    Cup. 

Simple    Gravity    Oil    Cup    Method. — One    of   the 

simplest    devices    for    supplying    lubricant    to    the    gas- 


23G  Thio  Modern  Gas  Tractor 

engine  cylinder  is  the  sight-feed  oil  cup,  which  has  been 
widely  employed  in  general  steam  engineering  practice 
for  some  time.  This  consists  of  an  oil  container  usually 
composed  of  metal  flanges  at  the  top  and  bottom  between 
which  a  glass  body,  which  permits  one  to  see  the  height 
of  oil  in  the  container,  is  fastened.  A  central  supply 
tube  terminates  in  a  small  compartment  under  the  main 
body  which  also  has  a  glass  wall  so  that  the  drops  of  oil 
may  be  seen  dripping  from  the  end  of  the  supply  tube. 
The  amount  of  oil  supplied  is  regulated  by  an  adjustable 
needle  valve  which  makes  it  possible  to  compensate  for 
differences  in  temperature  and  viscosity  of  the  oil  and 
keep  the  supply  to  the  amount  needed. 

The  application  of  a  sight-feed  oil  cup  is  outlined  at 
Fig.  87  though  this  shows  it  attached  to  the  wall  of  a 
two-cycle  engine  cylinder.  The  same  method  of  lubrica- 
tion would  apply  to  a  four-cycle  type  as  well.  It  will  be 
noticed  that  the  oil  is  supplied  to  the  cylinder  walls  at 
such  a  point  so  that  when  the  piston  is  at  the  bottom  of 
its  stroke  the  oil  supply  will  be  to  a  point  a  little  above 
the  wrist-pin.  As  the  piston  moves  up  the  oil  collects  in 
the  chamber  back  of  the  supply  pipe  until  the  hollow 
wrist-pin  registers  with  the  opening.  The  oil  flows  into 
the  wrist-pin  and  from  this  point  to  the  lower  crank- 
shaft bearing  through  a  small  copper  tube  which  con- 
nects the  upper  and  lower  connecting-rod  bearings. 
When  the  piston  reaches  the  top  of  its  stroke  oil  will 
flow  into  the  annular  oil  chamber  at  the  base  of  the  cylin- 
der, and  as  the  bottom  of  the  piston  dips  into  this  oil 
groove  at  the  end  of  every  down  stroke,  enough  oil  will 
be  carried  up  to  insure  adequate  lubrication  of  the 
cylinder  walls. 

The  sight-feed  oiler  needs  continual  attention,  so  most 
of  the  modern  tractors  are  provided  with  mechanical 


The  Modern  Gas  Tractor  237 

lubrication  systems.  When  a  positively  driven  oil  pump 
is  used  one  is  sure  that  oil  will  be  delivered  to  all  bearing 
points,  whereas  in  the  sight-feed  gravity  oiler,  if  the  oil 
thickens  up  or  if  the  opening  in  the  supply  pipe  becomes 
clogged  with  a  small  piece  of  lint  or  bit  of  wax,  the  oil 
feed  stops  and  unless  there  happens  to  be  a  considerable 
amount  in  the  crank  case  the  engine  may  be  injured  by 
the  failure  of  continuous  oil  supply. 


Fig.  88. — Sectional    View   of    Four    Cylinder    Engine    Showing 
Passages  for  Oil  Distribution  in  Crankshaft. 


Mechanical  Oiling  Systems. — The  simplest  pos- 
sible form  of  a  mechanical  oiling  system  and  one  that 
gives  very  good  results  in  practice  is  called  the  constant 
level  splash  system.  The  other  method,  which  calls  for 
the  use  of  a  multiple  positive  drive  oil  pump,  is  also  used 
to  some  extent.  At  Fig.  88  the  cross-sectional  view  of  a 
four-cylinder  four-cycle  power  plant  clearly  shows  the 


238 


The  Modern  (Jas  Tractor 


application  of  a  three-lead  positive  oil-pump  system. 
The  crank  shaft  is  provided  with  passages  indicated  by 
the  heavy  lines.  An  oil  lead  goes  to  each  main  bearing, 
and  after  it  has  served  its  purpose  there  the  oil  is  taken 
through  the  passage  in  the  crank  shaft  and  led  to  the 
four  connecting  rod  bearings,  from  which  it  is  thrown 
around  the  interior  of  the  motor  by  centrifugal  force 
from  the  rapidly  revolving  crank  shaft.  The  interior 
of  the  engine  is  filled  with  a  continual  mist  or  spray  of 
oil  and  all  parts  are  thoroughly  lubricated.  The  excess 
oil  drops  into  the  crank  case,  which  it  fills  to  the  level 


0ILTR6UGM5 


Fig.  89.— Method  of  Supplying  Oil  Troughs  of  Holt  Tractor 
Motor  Crankcase. 

determined  by  the  height  of  the  standpipes  in  each  crank- 
case  compartment.  This  height  is  just  enough  so  the 
lower  portions  of  the  connecting-rod  caps  just  skim  over 
its  surface  and  pick  up  some  of  the  lubricant  and  by 
splashing  it  around  the  interior  assist  materially  in  its 
distribution.  The  oil  is  supplied  to  the  main  bearings 
under  considerable  pressure  and  must  reach  these  bear- 
ing points.  From  that  point  the  distribution  is  auto- 
matic through  the  passage  drilled  in  the  crank  shaft 


The  Modern  Gas  Tractor 


239 


and  the  splashing  action  of  the  connecting  rods  as  they 
dip  into  the  oil  pools  in  the  compartments  at  the  lower 
portion  of  the  crank  case. 

The  lubricating  system  outlined  at  Fig.  89  shows 
clearly  the  method  of  oil  distribution  by  means  of  a 
connecting  rod.  The  oil  pump,  which  is  driven  by  means 
of  bevel  gearing  from  the  motor  cam  shaft,  draws  oil 
from  the  lower  portion  of  the  crank  case  and  delivers  it 


r*-«=5' 


MECHP!NlCf\L' 
OILER     ' 

E§zr 


Fig.  90. — Mechanical   Oiler  Attached  to  Motor, 
to  Cylinders  and  Timing  Gear  Case. 


Note  Leads 


to  a  manifold  pipe  which  supplies  four  troughs  extend- 
ing across  the  crank  case  and  into  which  the  connecting 
rods  dip  as  the  crank  shaft  revolves.  This  is  really  a 
constant  level  splash  system.  All  the  interior  parts  of 
the  motor  are  lubricated  by  the  oil  spray  produced  by 
the  rapidly  revolving  connecting  rod  big  ends. 

The  application  of  an  individual  lead-system  mechan- 
ical oiler  to  a  four-cylinder  engine  is  clearly  shown  at 


240 


The  Modern  Gas  Tractor 


Fig.  90.  It  will  be  observed  that  six  pipes  lead  from  the 
bottom  of  this  device,  four  of  which  go  directly  to  the 
cylinders  while  one  goes  to  the  timing-gear  case  at  the 
front  end  of  the  motor  and  the  remaining  one  directly 
to  the  crank-case  interior.  The  device  is  driven  by 
gearing  which  is  not  shown  in  the  illustration.  The  inter- 
ior of  the  mechanical  oiler  showing  a  sectional  view  taken 


. Lock  nut 

J*Adjustment  nut 


Chech  plunger  <^  Teed  tubeTo  Motor 


Fig.  91. — Sectional    View    of    Simple    Mechanical    Lubricator 
Showing  Parts. 


The  Modern  Gas  Tractor  241 

through  one  of  the  pumps  is  depicted  at  Fig.  91.  The 
pump  plunger  is  operated  by  means  of  a  metal  yoke 
which  rides  on  the  surface  of  the  operating  cam.  The 
yoke  is  kept  seated  against  the  cam  periphery  by  means 
of  the  yoke  spring,  and  when  the  parts  are  in  the  posi- 
tion shown  oil  can  flow  into  the  pump  cylinder  through 
the  two  small  holes  immediately  under  the  pump  plunger. 
As  the  oiler  cam  shaft  rotates,  carrying  the  cam  with  it, 
the  yoke  is  forced  down  by  means  of  the  yoke  spring 
and  the  pump  plunger  is  pushed  into  the  cylinder  with 
considerable  force,  this  displacing  the  oil  from  the  cylinder 
and  forcing  it  past  the  check  plunger  (which  opens  be- 
cause of  the  oil  pressure)  through  the  feed  tube  attached 
to  the  motor  by  a  conductor  of  flexible  copper  tubing. 

The  amount  of  oil  is  regulated  by  an  adjustment  nut 
which  may  be  screwed  up  or  down  on  the  stem  of  the 
yoke  which  projects  through  the  cover  of  the  device  and 
which  will  thus  limit  the  effective  stroke  of  the  pump 
plunger.  Obviously,  the  greater  the  stroke  the  more 
oil  will  be  supplied  at  each  revolution  of  the  cam  shaft 
and  each  downward  movement  of  the  yoke  to  which 
the  pump  plunger  is  attached.  The  number  of  pumps 
varies  with  the  number  of  bearings  that  are  to  be  sup- 
plied, and  as  a  general  rule  one  pump  is  allowed  for  each 
bearing  point.  Those  that  require  -large  amounts  of  oil 
are  arranged  so  the  full  stroke  of  the  pump  plunger  is 
utilized,  while  the  leads  that  do  not  require  much  oil  are 
joined  to  pumps  adjusted  with  a  very  short  stroke,  so 
the  quantity  of  oil  displaced  by  the  plunger  at  each 
revolution  of  the  cam  shaft  is  relatively  small.  The 
entire  interior  of  the  device  that  is  not  occupied  by 
machinery  serves  as  a  container  for  oil  and  a  sight-feed 
gauge  glass  set  into  one  corner  of  the  lubricator  body 
indicates  the  amount  of  oil  available  at  all  times. 


242 


The  Modern  Gas  Tractor 


Wafer  Ouf/ef 


Pipe 


r/oaf^ 


F//fer/n$  Screen 
OirOut/et 


Geared  O//  Pi/mp 


Fig.  92. — Sectional  View  of  Motor  Showing  Complete  Constant 
Level  Splash  Lubricating'  System. 

Constant  Level  Splash  System. — The  constant 
level  splash  system  has  become  very  popular  on  motor 
cars  and  is  also  widely  used  on  gas-tractor  power  plants 
that  are  based  on  automobile  engineering  practice.  The 
application  of  a  typical  system  of  this  kind  is  shown  at 


Tin-:  Modern  <1as  Tractor 


2i:\ 


Fig.  92,  and  in  view  of  the  clear  manner  in  which  the 
various  parts  are  outlined,  very  little  explanation  is 
necessary.  The  lubricant  is  carried  in  a  sump  or  oil 
container  at  the  bottom  of  the  crank  case  which  may  be 
filled  through  the  breather  pipe  conveniently  arranged 
at  the  top  of  the  crank  case  and  having  a  removable 
cap  to  permit  the  introduction  of  lubricant  to  the  crank 
case  interior.  The  oil  level  in  the  sump  is  shown  by 
means  of  an  oil  gauge  carried  by  a  small  float  which  falls 
when  the  oil  level  decreases  to  the  point  where  the  sup- 
ply in  the  crank  case  must  be  renewed. 


Fig.  93. 


-Method    of    Lubricating    Alain    Bearings    From    Oil 
Reservoirs  Integral  With  Crankease. 


The  oil  is  taken  from  the  sump  by  means  of  a  geared 
oil  pump  and  is  discharged  into  the  crank  case.  It  fills 
the  crank  case  to  the  level  determined  by  the  overflow 
pipe,  the  position  of  which  may  be  varied  as  desired  by 
rocking  it  in  its  bearings.  The  oil  level  is  usually  of  such 
height  that  will  permit  the  splasher  or  oil  scoop  on  the 
bottom  cap  of  the  connecting  rod  to  dip  into  it.  With 
this  system  all  of  the  interior  mechanism  is  lubricated 


244  The  Modern  Gas  Tractor 

by  means  of  the  oil  mist  produced  by  the  rapidly-revolv- 
ing crank  shaft.  All  excess  oil  supplied  flows  back  into 
the  sump  through  the  overflow  pipe  and  is  filtered 
through  the  screen  at  the  oil  outlet  before  it  is  again 
supplied  to  the  crank-case  interior.  In  this  manner 
only  clean  oil  is  supplied  and  one  filling  of  lubricant  will 
last  for  a  run  of  three  or  four  hundred  miles.  At  the  end 
of  this  period  all  the  old  oil  is  cleared  out  of  the  crank 
case  and  oil  sump  through  a  suitable  drain  cock  and  the 
supply  is  replenished  with  new,  unused  oil. 

In  the  systems  previously  outlined  the  main  bearings 
are  lubricated  either  by  oil  supplied  by  individual  leads 
or  by  a  mist  which  is  present  in  the  crank  case  all  times 
that  the  engine  is  in  operation.  Another  method  of 
lubricating  main  bearings,  which  has  been  applied  to 
stationary  engines  with  some  degree  of  success  and 
which  is  also  suitable  for  tractor  power  plants  where 
the  cylinder  is  oiled  from  a  sight-feed  oiler,  is  shown  at 
Fig.  93.  The  main-bearing  pedestal  is  cored  out,  as 
shown  at  C,  this  forming  an  oil  chamber  which  can  be 
filled  through  the  plug  D.  As  the  oil  level  at  C  is  higher 
than  the  bottom  of  the  bearing  oil  will  be  supplied  con- 
tinuously through  the  passageway  S  which  provides 
communication  between  the  shaft  and  the  oil  container. 
The  brasses  B  are  thus  covered  with  a  film  of  oil  which 
is  maintained  automatically  as  long  as  the  oil  level  in 
chamber  C  is  higher  than  the  bottom  of  the  bearing  B. 


CHAPTER  VII. 

FUNCTIONS  AND  CONSTRUCTION  OF  CLUTCH,  GEAR- 
SET  AND  DIFFERENTIAL. 

Why  Clutch  is  Needed — Action  of  Simple  Clutch  Described — 
Some  Typical  Tractor  Clutches — Friction  Disc  and  Roll 
Clutches — Why  Reversing  Mechanism  is  Needed — Typical 
Reversing  Mechanism — Why  Speed  Changing  is  Necessary 
— Action  of  Simple  Change  Speed  Gears  Outlined — The 
Differential  Gear  and  Its  Use. 

Why  Clutch  Is  Needed. — One  of  the  important 
members  of  the  power-transmission  system  of  the  gas 
tractor  is  the  friction  clutch  employed  to  connect  the 
power  plant  to  the  rear  wheels  or  to  break  the  driving 
connection  between  the  power  generating  and  traction 
members  when  desired.  A  clutch  is  absolutely  neces- 
sary on  a  gas  tractor,  though  on  a  steam  tractor  it  is 
not  customary  to  provide  a  clutch  between  the  engine 
and  the  driving  wheels,  though  in  some  cases  this  device 
is  furnished  on  the  steam-power  plant  as  well.  Steam 
engines  are  capable  of  delivering  power  considerably  in 
excess  of  their  rating,  and  as  the  steam  which  furnishes 
the  power  is  stored  under  pressure  in  the  boiler  it  is  pos- 
sible to  start  the  steam  engine  under  load.  The  amount 
of  power  delivered  from  a  steam  engine  may  be  varied 
by  regulating  the  quantity  and  pressure  of  the  steam 
going  to  the  cylinders  and  a  simple  throttle-valve  lever 
is  all  that  is  needed  to  control  the  speed  of  the  steam 
tractor  and  to  start  or  interrupt  the  drive  when  desired. 

245 


246 


The  Modern  (Jas  Tractor 


The  Modern  Gas  Tractor  247 

When  a  gasoline  engine  is  used  as  a  power  plant,  con- 
ditions are  radically  different.  It  is  not  possible  to  start 
any  explosion  motor  under  load,  because  the  power  is 
obtained  by  the  combustion  of  fuel  directly  in  the  cylin- 
ders and  there  is  no  external  source  of  energy  to  draw 
from,  as  is  the  case  with  the  steam  engine.  The  power 
produced  by  a  gasoline  engine  depends  upon  the  rapidity 
with  which  the  explosions  follow  each  other,  and  unless 
the  engine  is  turning  over  at  a  certain  speed,  it  is  not 
delivering  its  full  power.  It  has  been  demonstrated 
that  a  certain  cycle  of  operations  is  necessary  to  secure 
gasoline-engine  action.  For  example,  consider  the  case 
of  a  single-cylinder  engine,  started  under  load.  If  there 
was  a  charge  of  gas  already  in  the  cylinder  and  this  was 
exploded,  the  piston  might  make  one  stroke,  but  as  there 
would  be  no  further  energy  supplied,  the  crank  shaft 
would  come  to  a  stop  on  account  of  the  resistance.  It 
will  be  apparent,  therefore,  that  the  gasoline  engine 
must  revolve  free  of  load  in  order  to  start  it.  The  piston 
must  go  through  the  functions  of  drawing  in  a  charge 
of  gas,  compressing  it,  and  then  firing  it  before  any 
power  is  produced.  Even  after  the  engine  is  started,  it 
must  attain  a  certain  speed  to  supply  the  power  needed 
to  overcome  the  resistance  that  tends  to  prevent  motion 
of  the  tractor,  before  it  can  be  used  in  driving  it. 

It  is  very  desirable  that  the  gas  tractor  be  started  or 
stopped  independently  of  the  engine.  On  a  steam  trac- 
tor it  is  possible  to  start  it  as  soon  as  steam  is  admitted 
to  the  cylinder  from  the  boiler,  but  with  a  gasoline 
engine  it  is  customary,  and  in  fact  necessary,  to  inter- 
pose some  clutch  mechanism  between  the  engine  and 
driving  wheels,  which  will  make  it  possible  to  couple 
the  power  plant  to  the  traction  members  and  disconnect 
it  at  will.     The  friction  clutch  is  the  simplest  method  of 


248  The  Modern  Gas  Tractor 

accomplishing  this  result.  This  consists  merely  of  a 
locking  member,  which  is  capable  of  joining  the  driving 
shaft  to  the  crank  shaft  of  the  engine  when  desired.  The 
location  of  a  typical  clutch  is  clearly  shown  at  Fig.  94, 
as  applied  to  a  gas  tractor.  The  clutch  is  usually  oper- 
ated by  a  hand  lever  and  as  a  rule  the  leverage  is  propor- 
tioned so  that  but  little  effort  is  needed  on  the  part  of  the 
operator  to  apply  or  release  the  power. 

Action  of  Simple  Clutch  Described. — Clutches 
that  utilize  the  driving  properties  of  frictional  adhesion 
have  proven  to  be  the  most  satisfactory  in  practical 
application.  The  most  important  requirement  is  that 
the  clutch  be  capable  of  transmitting  the  entire  power 
of  the  engine  to  which  it  is  fitted  without  any  loss  due 
to  slipping.  The  clutch  should  also  take  hold  gradually 
because  any  "grabbing"  will  produce  stresses  that  may 
seriously  injure  the  mechanism.  It  is  imperative  that 
the  two  portions  of  a  clutch  member  disengage  positively 
when  the  clutch  is  released  so  that  there  will  be  no 
dragging  or  rotation  of  parts.  Other  factors  to  be  con- 
sidered are  to  provide  as  much  friction  surface  as  pos- 
sible, to  have  the  clutch  members  placed  in  an  accessible 
position,  and  to  provide  adjustment  so  a  certain  amount 
of  wear  can  be  taken  up. 

A  simple  friction  clutch  such  as  used  in  transmitting 
power  from  one  shaft  to  another  is  shown  at  Fig.  95, 
which  illustrates  all  the  important  parts  of  the  mechan- 
ism. The  clutch  ring  K  is  about  half  the  diameter  of 
the  pulley  and  is  attached  to  the  arms  or  spokes  by 
casting  integral  in  some  cases  and  by  making  it  a  separ- 
ate bolted  member  in  others.  The  inner  jaws  Q  on  each 
arm  are  forced  outward  and  the  outer  jaws  H  inward  by 
means  of  the  toggle  levers  SU  which  operate  upon  the 
levers  E.     This  lever  has  its  fulcrum  between  its  points 


The  Modern  Gas  Tractor 


249 


Fig.  95. — Sectional  View  of  Simple  Clutch,  Showing  Principal 

Parts. 

of  connection  with  friction  members  Q  and  H  and  is 
operated  by  means  of  a  inclined  cam  member,  which  is 
lifted  by  a  roller  or  contact  member  carried  at  the  end 
of  the  bell-crank  lever  U.  As  will  be  evident  the  friction 
members  Q  act  against  the  inner  periphery  of  the  cast- 
iron  clutch  ring  K  while  the  friction  members  H  act 
against  the  outer  periphery  of  the  same  member.  Four 
to  six  sets  of  friction  members  are  provided,  and  when 
the  bell  crank  U  is  operated  by  the  toggle  S,  the  end 


iT)!!  The  Modern  Gas  Tractor 

of  the  rocker  lever  F  which  carries  the  cam  E  is  raised. 
This  pushes  the  shoe  Q  up  and  pulls  down  the  shoe  H. 
The  shoe  H  is  provided  with  a  friction  block  of  well- 
seasoned  maple  X  and  the  shoe  Q  is  provided  with  a 
friction  member  of  the  same  material  at  Y. 

The  belt  pulley  revolves  on  a  bushing  which  turns 
freely  on  the  driving  shaft  when  the  clutch  is  discon- 
nected. The  spider  that  carries  the  clutch  members 
Q  and  H  and  their  actuating  mechanism  is  keyed  to  the 
shaft  and  revolves  with  it.  To  engage  the  clutch  the  col- 
lar Z  is  pushed  toward  the  pulley,  this  clamping  the  ring 
attached  to  the  pulley  firmly  between  the  driving  shoes 
which  are  revolving  with  the  shaft.  When  the  pulley  is 
locked  to  the  revolving-clutch  member  it  must  turn  with 
it  and  at  the  same  speed  because  the  lock  is  positive.  If 
the  friction  blocks  slip  considerable  power  will  be  lost 
in  transmission.  To  release  the  clutch  the  collar  Z  is 
pulled  away  from  the  pulley  and  the  jaws  Q  and  H 
spread  apart,  allowing  the  cast-iron  driving-ring  K  to 
revolve  freely  between  them.  In  this  way  it  will  be  seen 
that  motion  may  be  imparted  to  a  stationary  shaft  by 
means  of  a  revolving  pulley  or  vice  versa. 

Some  Typical  Tractor  Clutches. — A  very  efficient 
type  of  clutch  used  on  the  Holt  tractors  is  shown  at  Fig. 
96.  This  is  a  three-plate  type  and  the  cast-iron  ring 
which  acts  as  a  driving  member  is  clamped  between  the 
two  driven  members  in  much  the  same  manner  as  pre- 
viously explained.  The  engine  fly-wheel  carries  a  clutch 
casing  in  which  a  floating  driving  plate  is  keyed.  This 
plate  must  turn  with  the  fly-wheel  but  may  move  back 
and  forth  on  its  keys.  The  engine  crank  shaft  termin- 
ates in  the  hub  of  the  fly-wheel  while  the  drive  is  taken 
up  by  an  independent  shaft  which  runs  into  a  telescopic 
bearing  of  the  plain  bushing  type  carried  in  the  hub  of 


The  Modern  Gas  Tractor 


251 


Clutch  Dn'uing  Member 


Clutch  Driving  Plate- 
Bell  Crank, 


^Flywheel  Rim 


'Flywheel  Hub 


'Clutch  Shifting  Rod 


Fig.  90. — Sectional    View    of    Master    Clutch    Used    on    Holt 
Tractors. 

the  clutch  case.  The  engine  shaft  and  drive  shaft  are 
independent  when  the  clutch  is  disengaged.  That  is  to 
say,  the  drive  shaft  may  remain  stationary  while  the 


252  The  Modern  Gas  Tractor 

fly-wheel  revolves.  Attached  to  the  driving  shaft  is  a 
flanged  member  which  carries  a  number  of  bell  cranks 
spaced  equidistantly  or  120  degrees  apart.  This  driven 
member  also  carries  a  plate  which  is  keyed  to  it  and  which 
must  revolve  with  the  driven  shaft.  This  plate  can  move 
back  and  forth  on  its  key  so  the  two  clutch-driven  plates 
are  in  contact  with  the  driving  plate  only  when  the 
clutch  lever  has  moved  the  clutch-link  actuator  to  the 


CLUTCH 


CLUTCH    BLOCK 

BELT_P_ULLEY 

BELT  PULL  ELY 
BRAKE 


CLUTCH   SHIFTING 
BE.LL   CRANK 


UTCH     BLOCK 


Fig.  97.— Clutch   of   Avery   Tractor   is   Provided   With   Three 
Clutch  Shoes. 

position  shown,  where  the  toggle  links  are  approximately 
vertical  and  the  bell  cranks  are  holding  the  driven  and 
driving  plates  of  the  clutch  into  firm  engagement. 

When  the  clutch-link  actuator  is  moved  back  the  bell 
crank  is  pulled  away  from  the  outer  clutch-driven  plate, 
and  as  there  is  no  pressure  to  maintain  frictional  contact 


The  Modern  Gas  Tractor 


253 


between  the  driven  and  driving  members,  the  fly-wheel 
of  the  motor  may  continue  to  revolve  while  the  mechan- 
ism attached  to  the  drive  shaft  becomes  stationary. 
Wear  between  the  clutch  plates  may  be  taken  up  by  an 
adjustable  contact  member  carried  by  the  bell  crank. 
A  clutch  of  this  type  may  be  applied  gradually  and  may 


Fig.  98.— Clutch   of   Rumely   Tractor   Utilizes   Three   Friction 
Shoes  Acting  on  Interior  of  Wheel  Rim. 

be  allowed  to  slip  to  some  extent  while  getting  the  trac- 
tor under  way  without  doing  any  injury.  When  the 
clutch  lever  is  operated  to  the  limit  of  its  movement  in 
one  direction  the  clutch  is  firmly  engaged,  while  moving 


254  The  Modern  Gas  Tractor 

it  to  the  other  extreme  position  will  insure  complete  dis- 
engagement. 

Clutches  shown  at  Figs.  97  and  98  are  similar  in  con- 
struction. In  these  a  series  of  contact  blocks  are  carried 
at  the  end  of  counter-balanced,  pivoted  levers.  The 
blocks  are  pushed  out  by  means  of  a  toggle  linkage 
actuated  by  a  clutch-shifting  bell  crank,  in  much  the 
same  manner  as  has  been  previously  described.  One 
member  is  attached  to  the  crank  shaft  while  the  other 
rotates  with  the  driving  shaft.  The  clutch  shown  at 
Fig.  97  is  used  to  bring  a  belt  pulley  into  engagement 
with  the  engine  shaft,  though  the  principle  may  be 
reversed  and  the  belt  pulley  represent  a  member  at- 
tached to  the  engine  fly-wheel  while  the  spider  which 
carries  the  clutch  blocks  and  actuating  mechanism  would 
be  attached  to  the  independent  transmission  shaft. 

Friction  Disk  and  Roll  Clutches. — Some  tractor 
designers  employ  friction-wheel  clutches  instead  of  the 
types  described  These  operate  on  a  different  principle 
as  the  members  are  not  locked  together  so  that  they 
revolve  as  a  unit,  but  the  driven  member  rotates  the 
driving  member  which  turns  on  a  different  plane.  A 
double  friction  disk  clutch  such  as  used  on  the  Heider 
is  shown  at  Fig.  99,  and  its  relation  to  the  engine  may 
be  clearly  ascertained.  The  fly-wheel  has  a  fiber  ring 
attached  to  it  which  serves  as  a  driving  member,  while 
two  disks  are  attached  to  the  cross  shaft  which  is  placed 
at  right  angles  to  the  crank  shaft  of  the  motor.  These 
disks  are  adapted  to  be  brought  into  contact  with  the 
fiber  friction  ring  with  a  considerable  degree  of  pressure. 

The  sketch  at  Fig.  100  shows  the  principle  of  opera- 
tion. If  the  engine  fly-wheel  is  turning  in  the  direction 
indicated  by  the  arrow  and  the  friction  disk  A  is  brought 
in  contact  with  it,  the  cross  shaft  to  which  the  disk  A  is 


The  Modern  Gas  Tractor 


Zoo 


256  The  Modern  Gas  Tractor 

attached  will  turn  in  the  same  direction,  and  as  this 
carries  a  driving  pinion  which  is  in  mesh  with  a  driving 
gear  on  the  differential  casing  of  the  counter  shaft  it 
will  turn  it  in  the  opposite  direction.  As  the  connection 
from  the  counter  shaft  to  the  rear  wheels  is  by  chain  and 
sprockets  the  rear  wheels  will  turn  in  the  same  direction 
as  the  counter  shaft  does  and  the  entire  machine  will 
move  in  the  direction  of  the  large  arrow  or  forward.  If 
conditions  are  reversed  and  the  friction  disk  A  is  pulled 
out  of  engagement  with  the  fly-wheel,  while  friction 
disk  B  is  brought  in  contact  with  that  member,  the  trac- 
tor will  move  backward  because  friction  disk  B  will  be 
revolved  in  a  direction  opposite  to  that  friction  member 
A  turns  in. 

Another  form  of  friction  clutch  in  which  a  friction 
wheel  is  employed  is  shown  at  Figs.  101  and  102.  The 
view  of  the  mechanism  at  Fig.  101  shows  clearly  the 
mounting  of  the  friction  wheels  for  driving  a  movable 
cross  shaft,  which  in  this  case  is  parallel  with  the  engine 
crank  shaft.  This  main  driving  shaft,  which  extends 
across  the  frame,  is  provided  with  a  friction  driving 
wheel  at  each  end  and  carries  a  pair  of  sliding  gears 
which  may  be  engaged  with  either  one  or  two  gears  on 
the  transmission  cross  shaft  placed  immediately  back  of 
the  main  driving  shaft  that  carries  the  friction  wheels. 
The  gears  on  the  transmission  cross  shaft  are  of  different 
diameters,  one  being  smaller  than  the  other,  as  is  true  of 
the  sliding  gears  on  the  squared  main  shaft.  Before  dis- 
cussing the  method  of  obtaining  speed  changes  or  final 
drive  it  will  be  well  to  consider  the  action  of  the  friction 
rollers. 

The  engine  carries  two  large  fly-wheel  members,  which 
are  so  arranged,  one  at  each  side  of  the  frame,  that  the 
friction  wheels  employed  for  driving  fit  in  an  annular 


The  Moderx  Gas  Tractor 


258 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  259 

channel  machined  between  the  inner  and  outer  fly-wheel 
members.  This  is  clearly  shown  at  Fig.  102-A.  The 
fly-wheel  hub  is  enlarged  and  forms  one  driving  member 
while  the  fly-wheel  rim,  which  has  a  smooth  and  true 
inner  periphery,  forms  the  other  driving  member.  When 
the  friction  driving  wheels  carried  by  the  transmission 
main  shaft  are  in  the  neutral  position  they  are  in  the 
space  between  the  inner  and  outer  fly-wheel  driving 
members,  and  as  the  friction  roller  is  not  in  contact  with 
either  the  hub  or  the  rim  of  the  fly-wheel,  one  member 
may  revolve  independently  of  the  other. 

To  obtain  the  forward  drive,  the  main  shaft  is  rocked 
so  the  friction  wheels  are  brought  in  contact  wTith  the 
inside  of  the  fly-wheel  rim.  If  this  is  turning  in  the  di- 
rection indicated  by  the  arrow,  it  will  turn  the  friction 
roller  in  the  same  direction,  and  the  main  shaft  is  revolv- 
ing in  the  same  direction  as  the  motor  crank  shaft.  To 
obtain  a  reverse  motion  of  the  main  shaft  the  friction 
rollers  are  disengaged  from  the  interior  of  the  fly-wheel 
rim  and  are  pushed  against  the  exterior  of  the  fly-wheel 
hub,  as  indicated  at  C.  This  will  produce  a  motion  of 
the  main  shaft  opposite  in  direction  to  that  of  the  crank 
shaft.  The  leverage  is  proportioned  so  that  very  little 
pressure  is  necessary  at  the  operating  lever  to  insure 
positive  drive.  The  shaft  on  which  the  friction  pulleys 
are  keyed  is  hung  on  pivoted  or  eccentric  bearings, 
which  are  located  in  such  a  way  that  when  the  friction 
surfaces  are  brought  in  contact  with  each  other  they 
will  automatically  produce  pressure  enough  to  move  the 
load,  and  as  the  resistance  augments  the  driving  pressure 
becomes  stronger  and  the  rolls  can  transmit  the  full 
amount  of  power  generated  by  the  engine.  The  friction 
wheels  are  made  of  paper  or  strawboard  fiber  and  may  be 
very  easily  replaced  when  worn. 


260 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  261 

It  is  claimed  that  the  friction  drive  methods  cannot 
be  compared  to  the  friction  clutch  because  it  will  give  a 
much  smoother  and  more  flexible  drive  than  is  possible 
with  any  form  of  friction  clutch.  It  is  contended  that 
the  clutch  is  too  positive  a  lock  betwreen  the  driving  and 
driven  parts,  while  the  friction  rollers  are  not  so  positive 
in  their  action.  It  is  also  advanced  that  in  event  of  sud- 
den shock  the  friction  roller  will  slip  to  some  extent,  while 
with  the  friction  clutch,  which  is  positively  locked,  a 
sudden  strain  will  result  in  breaking  a  gear  or  stressing 
of  some  of  the  transmission  parts.  With  either  of  the 
friction  drives  described,  a  one-lever  clutch  control  is 
obtained  and  one  can  stait,  stop,  or  reverse  the  tractor 
instantly  by  using  but  one  control  lever. 

The  methods  of  obtaining  the  changes  of  speed  on  the 
Ohio  tractor  may  be  easily  understood  by  referring  to 
illustration,  Fig.  101.  If  the  sliding  gears  are  shifted 
along  the  main  shaft,  so  that  the  smallest  pinion  on  the 
main  shaft  is  in  mesh  with  the  largest  gear  on  the  trans- 
mission cross  shaft  the  slowest  rear-wheel  speed  is  ob- 
tained. If  the  largest  pinion  on  the  main  shaft  is  slid 
into  engagement  with  the  smallest  gear  on  the  transmis- 
sion cross  shaft  the  highest  rear-wheel  speed  will  be 
obtained.  If  the  sliding-gear  member  on  the  main  shaft 
is  placed  at  a  neutral  position  so  that  it  is  not  in  mesh 
with  either  gear  on  the  cross  shaft,  engaging  the  friction 
wheels  and  the  fly-wheel  will  not  produce  motion  of  the 
tractor.  The  drive  from  the  transmission  cross  shaft 
is  by  a  pinion  which  engages  a  large  gear  attached  to  the 
differential  spider.  The  differential  gear  is  attached  to 
a  cross  shaft  to  which  the  bull  pinions,  which  drive  the 
bull  gears  on  the  rear  wheels,  are  attached.  It  will  be 
apparent  that  with  the  friction  roll  clutch  it  will  be 
possible  to  obtain  the  same  number  of  speeds  on  the 


2G2 


The  Modern  Gas  Tractor 


FLYWHEEb 

CLUTCH 


DRIVING 
GEAR 


OPERATING 
I    LEVER 


BEVEL 
GEAR 

—A 


BE\(EL 
EAR 

5 


BULL 
PINION 


FRAME 
CASTING       OULL 
PINION 


[STARTING    CRANK 


Fig.  103. — Master  Clutch  and  Reversing  Mechanism  of  Typical 

Tractor. 

reverse  drive  as  when  the  tractor  is  moving  ahead. 
Why  Reversing  Mechanism  Is  Needed. — Another 
difference  between  the  steam  and  gas  engines  used  for 
tractor  propulsion  is  that  the  direction  of  crank-shaft 
rotation  of  the  former  may  be  easily  reversed  by  a  sim- 


The  Modern  Gas  Tractor  263 

pie  mechanism  which  will  reverse  the  flow  of  steam  to 
the  cylinders  while  the  latter,  as  ordinarily  made,  can 
only  run  in  one  direction.  When  a  steam  engine  is  used 
for  power  no  separate  reversing  mechanism  is  needed, 
but  when  the  gas  engine  is  utilized,  owing  to  the  fact  that 
it  runs  only  in  one  direction,  it  is  necessary  to  provide 
some  form  of  gearing  that  will  permit  the  motion  of  the 
road  wheels  to  be  reversed  even  if  the  engine  continues  to 
revolve  in  the  same  direction  as  when  the  tractor  is 
moving  ahead. 

Typical  Reversing  Mechanism. — A  simple  and 
efficient  form  of  reversing  mechanism  is  shown  at  Fig. 
103.  It  consists  of  two  bevel  pinions  placed  on  a  con- 
tinuation of  the  engine  shaft  and  a  bevel  gear  at  right 
angles  to  them  and  in  mesh  with  both  of  the  pinions. 
The  bevel-gear  shaft  carries  a  driving  pinion  of  the  spur 
type  which  meshes  with  the  differential  driving  gear 
which  in  turn  imparts  motion  to  the  bull  pinions  mounted 
on  the  counter  shaft.  The  bevel  pinions  of  the  reversing 
gear  normally  revolve  freely  on  the  engine-shaft  exten- 
sion if  the  double-jaw  clutch,  which  is  keyed  to  the 
driving  shaft,  is  in  its  neutral  position.  A  master  clutch 
is  placed  inside  the  engine  fly-wheel  so  the  driving  shaft 
which  carries  the  positive  jaw  clutch  member  may  be 
placed  out  of  engagement  with  the  power  plant  when 
desired.  The  double  positive  clutch  may  be  moved  back 
and  forth  so  that  it  can  clutch  either  bevel  gear  A  or 
bevel  gear  B  to  the  driving  shaft.  When  in  the  neutral 
position,  if  the  master  clutch  is  engaged,  the  tractor 
will  not  move  because  there  is  no  driving  connection 
between  the  bevel  gearing  and  the  driving  shaft. 

When  the  positive  jaw  clutch  is  moved  on  the  shaft 
so  it  engages  bevel  gear  A  the  drive  is  through  A  to  the 
bevel  gear  on  the  short  cross  shaft  and  from  thence  to 


264 


The  Modern  Gas  Tractor 


ENGINE  FLYWHEEL 

STEERING  WHEEL 
/ 


MASTER 
CLUTCH 


REVER5E 
GEAR    A 


BELT  PULLEY 


BtV 
PINION 


DRIVE 
CHAIN 


CROSS  SHAFT  DRIVE  GEAR 


Fig.  104. — Showing  Arrangement  of  Clutches  and  Drive  Gears 
of  Holt  Caterpillar  Tractor. 


The  Modern  Gas  Tractor  2(;."> 

the  differential  gear  which  turns  the  counter  shaft  on 
which  the  bull  pinions  are  mounted,  so  the  tractor  is 
moving  ahead.  If  the  clutch  is  engaged  with  bevel  gear 
B,  the  motion  of  the  short  cross  shaft  is  reversed,  and 
as  the  train  of  gearing  runs  in  the  opposite  direction  to 
that  which  obtains  when  bevel  gear  A  is  clutched,  the 
tractor  will  move  backward. 

Another  form  of  reversing  gear,  which  operates  on 
practically  the  same  principle,  is  shown  at  Fig.  104. 
This  is  applied  to  the  Holt  Caterpillar  Tread  Tractor. 
In  this  mechanism,  instead  of  the  reduction  between 
the  driving  shaft  and  the  cross  shaft  being  by  means  of 
spur  pinion  and  gear,  the  drive  is  accomplished  by  a 
bevel  pinion  which  drives  the  cross-shaft  drive  gear. 
The  power  is  transmitted  from  the  cross-shaft  drive  gear 
to  the  shaft  on  which  small-diameter  sprockets  are 
mounted  and  from  these  driving  chains  are  connected 
to  the  large  driving  sprockets  which  move  the  cater- 
pillar tread  traction  member.  The  shaft  from  the  master 
clutch  is  continued  right  through  the  reverse-gear  box 
to  a  bearing  placed  between  the  cross-shaft  drive  gear 
and  one  of  the  traction  member  clutches.  To  obtain 
forward  motion  the  clutch  is  moved  so  that  it  locks  the 
bevel  gear  B  which  carries  at  the  other  end  of  the  sleeve 
on  which  it  is  mounted  the  main  bevel  drive  pinion,  and 
this  is  turned  in  the  same  direction  and  at  the  same 
speed  as  the  engine  crank  shaft  when  the  master  clutch 
in  the  engine  fly-wheel  is  engaged.  If  the  positive  clutch 
is  moved  toward  the  front  of  the  tractor  so  that  it  is 
clutched  to  the  reverse  gear  A  this  member  is  locked  to 
the  drive  shaft  and  the  drive  is  then  through  the  inter- 
mediate bevel  pinion  which  causes  the  forward  drive 
gear B to  turn  in  a  reverse  direction  and  thus  makes  the 
tractor  run  backward.       Sometimes  the  reverse  gear  is 


266  The  Modern  Gas  Tractor 

incorporated  with  the  change  speed  gearing  as  in  auto- 
mobile practice,  and  on  other  forms  of  tractors  it  may  be 
made  a  function  of  the  friction  disk  or  roll  clutches  as 
has  been  previously  described. 

Why  Speed  Changing  Is  Necessary. — Those  who 
are  familiar  with  the  action  of  steam  tractors  may  not 
recognize  the  necessity  for  change-speed  gearing  which 
is  such  an  essential  component  of  the  gas-motor-pro- 
pelled tractor.  It  has  been  demonstrated  that  the  steam 
engine  is  more  flexible  than  the  gas  engine  and  that  the 
amount  of  power  obtained  can  be  varied  by  altering  the 
amount  of  steam  admitted  to  the  cylinders.  If  the 
engine  is  running  slowly  and  more  power  is  needed  the 
engine  capacity  may  be  increased  materially  without 
augmenting  the  speed  of  rotation  and  the  power  may  be 
increased  50  or  100  per  cent  by  using  steam  at  higher 
pressure. 

The  internal  combustion  motor  is  flexible  to  a  certain 
degree,  provided  that  it  is  operating  under  conditions 
that  are  favorable  to  accelerating  the  motor  speed  by 
admitting  gas  to  the  cylinders.  The  power  capacity  or 
the  mean  effective  pressure  of  the  explosion  in  the  gas- 
engine  cylinder  is  limited  arbitrarily,  and  after  a  certain 
point  is  reached  it  is  not  possible  to  increase  the  power 
output  by  supplying  vapor  at  high  pressure  as  is  possible 
with  a  steam  engine.  It  is  customary  in  all  tractors  of 
the  gasoline  or  kerosene  burning  type,  where  combus- 
tion takes  place  directly  in  the  cylinders,  to  interpose 
change-speed  gearing  which  will  give  two  or  more 
ratios  of  speed  between  the  engine  and  the  traction 
members. 

There  are  occasions  when  a  tractor  is  required  to  pull 
a  heavy  load  slowly,  as  in  plowing,  where  it  is  desir- 
able not  to  exceed  a  speed  of  two  miles  an  hour,  whereas 


The  Modern  Gas  Tractor  267 

in  other  work,  as  in  hauling  on  the  road  or  moving  from 
place  to  place  without  a  load,  considerable  time  would 
be  lost  if  the  tractor  was  operated  on  the  low  speed. 
Four  or  five  miles  an  hour  is  a  practical  speed  for  hauling 
and  usually  some  means  is  provided  so  the  ratio  of  drive 
between  the  engine  and  the  rear  wheels  may  be  in- 
creased. On  some  tractors  three  changes  of  speed  are 
provided,  in  addition  to  a  reverse  motion,  combined  in 
the  gear  set.  Most  of  the  tractors  in  general  use,  how- 
ever, have  but  two  changes  of  speed,  while  man}-  very 
practical  machines  have  but  one  speed  forward  and 
reverse.  Where  the  reverse  gearing  is  incorporated  in 
the  change-speed  gear  set,  but  one  ratio  of  drive  is  pos- 
sible when  the  reverse  gears  are  engaged,  whereas  when 
a  separate  reversing  mechanism  is  utilized  in  connection 
with  a  change-speed  gearing,  as  many  speeds  backward 
as  there  are  forward  may  be  obtained. 

Action  of  Simple  Change=speed  Gears  Outlined. 
— In  order  to  explain  the  method  of  operation  of  a  sim- 
ple change-speed  gear  set,  the  essential  e  ements  of  a 
mechanism  of  this  character  are  shown  at  Fig.  105.  A 
gear  attached  to  the  engine  crank  shaft  A  drives  the 
cross -shaft  B.  This  carries  a  pair  of  sliding-gear  mem- 
bers, which  are  keyed  to  it  so  that  they  must  turn  at  the 
same  speed,  but  which  may  be  shifted  so  they  will  engage 
the  gears  on  the  cross  shaft  C,  which  in  turn  drives  the 
rear  wheels  by  means  of  pinions  which  mesh  with  the 
large  gears  attached  to  the  traction  members.  One  of 
the  gears  attached  to  the  differential  casing  is  24  inches 
in  diameter,  the  other  gear  is  27  inches.  The  small 
sliding  pinion  which  is  adapted  to  engage  with  a  24-inch 
gear  is  8  inches  in  diameter,  while  that  which  will  mesh 
with  the  larger  or  27-inch  gear  is  but  5  inches  in  diameter. 
Obviously,  these  dimensions  are  presented  only  to  make 


268 


Tin:  Modern  Gas  Tractor 


A/y>v/7ee/. 


'*a/~/ny 


^3  Dr/i//f}<?  P/'n/br? 


JJ/frerenft'a/ 


Fig.  105. — Diagram  Showing  Action  of  Speed  Changing  Gearing. 

the  explanation  clear  and  are  not  necessarily  dimensions 
that  will  be  used  in  practical  service. 

We  will  assume  that  the  driving  gear  on  the  engine 
crank  shaft  is  8  inches  in  diameter  and  meshes  with  a 
large  driving  gear  on  the  cross  shaft  B  which  is  24  inches 
in  diameter.    This  means  that  cross  shaft  B  will  turn  at 


The  Modern  Gas  Tractor  269 

one-third  the  speed  of  crank  shaft  A.  If  the  8-inch  gear 
on  the  cross  shaft  B  is  meshed  with  the  24-inch  gear  on 
the  differential  cross  shaft  C  the  shaft  C  will  revolve  at 
one-third  the  speed  of  shaft  B.  If  the  shaft  C  carries  a 
pinion  8  inches  in  diameter,  which  meshes  with  a  bull 
gear  48  inches  in  diameter,  the  rear  wheel  will  turn  at 
one-sixth  the  speed  of  the  differential  cross  shaft.  As- 
sume that  the  crank  shaft  A  of  the  engine  is  making  600 
revolutions  per  minute,  then  cross  shaft  B  will  revolve 
at  one-third  its  speed  or  two  hundred  revolutions  per 
minute.  On  account  of  the  reduction  between  the  cross 
shaft  B  and  the  differential  shaft  C  the  speed  of  the  lat- 
ter will  be  reduced  to  one-third  of  that  of  the  former  or 
66.66  revolutions  per  minute.  There  is  a  reduction  of 
six  to  one  between  the  large  bull  gear  on  the  wheel  and 
the  bull  pinion  on  the  differential  shaft,  so  the  rear  wheels 
will  turn  but  10.11  revolutions  per  minute.  Assuming 
that  the  driving  wheels  of  the  tractors  are  72  inches  in 
diameter,  which  gives  a  circumference  of  18.85  feet,  it 
will  be  evident  that  it  will  take  280  revolutions  of  the 
wheel  to  cover  one  mile.  As  the  rear  wheel  makes  ap- 
proximately ten  revolutions,  this  will  be  equivalent  to  a 
speed  about  one  mile  in  twenty-eight  minutes  or  a  little 
faster  than  two  miles  an  hour. 

Suppose  that  a  still  slower  speed  than  two  miles  an 
hour  is  desired,  then  the  5-inch  pinion  on  the  cross  shaft 
B  will  be  engaged  with  the  27-inch  gear  on  the  differen- 
tial cross  shaft.  The  ratio  of  drive  between  B  and  C 
will  then  be  lower.  If  cross  shaft  B  turns  at  200  revolu- 
tions per  minute  and  the  ratio  of  drive  is  as  five  to 
twenty-seven,  which  is  equal  to  a  ratio  of  5.40  to  1,  this 
means  that  the  cross  shaft  C  will  revolve  at  about  37 
revolutions  per  minute  instead  of  66,  and  the  speed  will 
be  reduced  to  less  than  one  mile  an  hour.    If  it  is  desired 


L»70  The  Modern  Gas  Tractor 

to  increase  the  speed  of  the  tractor  to  4  miles  an  hour  on 
the  high  speed  and  2  miles  an  hour  on  the  slow  speed, 
it  is  only  necessary  to  change  the  ratio  of  drive  between 
the  engine  crank  shaft  A  and  the  cross  shaft  of  the  trans- 
mission B.  The  speed  may  be  also  augmented  by  using 
a  16-inch  bull  pinion  instead  of  the  8-inch  diameter 
member. 

A  typical  plan  view  which  outlines  the  relation  of  the 
various  parts  of  the  driving  and  change-speed  mechan- 
ism of  the  Morris  Tractor  is  shown  at  Fig.  106.  In  this 
the  engine  crank  shaft  is  mounted  across  the  frame  and 
parallel  with  the  transmission  and  differential  cross  shaft 
and  the  rear  axle.  The  change-speed  gearing  is  mounted 
on  the  transmission  cross  shaft,  and  consists  of  two  gears 
which  are  in  mesh  with  two  driving  members  carried  by 
the  clutch  sleeve  mounted  on  the  crank-shaft' extension. 
These  gears  are  brought  in  engagement  with  the  trans- 
mission cross  shaft  on  which  they  normally  revolve 
free  by  a  sliding  internal  clutch  which  drives  the  trans- 
mission cross  shaft,  by  a  squared  end.  If  this  jaw  clutch 
is  moved  out  to  the  limit  of  its  travel  the  larger  speed- 
reduction  gears  are  engaged,  whereas  if  the  internal 
clutch  is  moved  to  the  limit  of  its  travel  toward  the 
frame  member,  the  larger  of  the  two  gears  on  the  cross 
shaft  is  engaged  with  the  smallest  driving  gear  on  the 
crank  shaft.  When  in  the  position  shown  in  drawing 
the  cross  shaft  gear-driving  clutch  is  in  a  neutral  posi- 
tion and  the  motor  may  turn  without  producing  any 
movement  of  the  cross  shaft.  The  gear  which  acts  as  a 
driving  member  to  turn  the  large  gear  attached  to  the 
differential  casing  is  normally  free  to  revolve  on  the 
transmission  cross  shaft  and  is  in  mesh  with  a  gear  car- 
ried on  a  small  shaft  below  it  at  all  times  as  well  as  with 
the   differential   drive   gear.      The   reverse    cross   shaft 


Pijr_  106 — ,   Sliced  Changing  Mechanism  and  Bear  Axle. 


Vis.  108— Plan  View  of  Morris  Tractor  Mechan 


if    Kimiiio   I'l-anl-shaft,    S|iccil  Cliansin-  M.-.-lianisu.  ami   Hear  Ax 


The  Modern  Gas  Tractor  271 

carries  another  gear  which  engages  with  a  normally 
freely-revolving  member  placed  near  the  frame  member 
on  the  other  end  of  the  transmission  cross  shaft.  These 
four  gears  are  always  in  mesh. 

When  it  is  desired  to  drive  the  tractor  forward,  the 
transmission  cross  shaft  is  made  to  drive  the  go-ahead 
gear  by  a  direct  connection  produced  by  a  positive  jaw 
clutch  which  clutches  the  loose  gear  so  that  it  must  turn 
with  the  transmission  cross  shaft.  To  obtain  a  reverse 
motion  the  forward  drive  clutch  is  pulled  out  of  engage- 
ment and  the  reverse  or  back-up  clutch  at  the  other 
side  of  the  square  portion  of  the  transmission  cross  shaft 
is  engaged  with  its  gear.  The  drive  is  then  from  the 
cross  shaft  to  the  gear  which  has  been  clutched  by  the 
back-up  clutch  member  and  from  thence  to  the  reverse 
counter  shaft,  back  from  this  to  the  differential  driving 
gear  through  the  medium  of  the  differential  gear  drive 
pinion  which  is  revolving  idly  on  the  shaft  and  serving 
merely  to  transmit  the  reverse  motion  produced  by  the 
reverse  cross  shaft,  thence  to  the  large  driving  gear 
attached  to  the  differential  casing.  The  speed  reduc- 
tion between  the  traction  members  and  the  differential 
cross  shaft  is  accomplished  by  means  of  bull  pinions 
which  drive  the  traction  member  by  internal  spur  bull 
gears  attached  to  the  wheel  rim  by  means  of  an  angle 
plate. 

A  change  speed  gearing  in  which  .speed  changes  as 
well  as  reverse  gearing  are  incorporated  in  one  unit  is  out- 
lined at  Fig.  107.  The  drive  from  the  engine  is  by  a 
chain  to  the  large  driving  sprocket  which  drives  the 
gear  A  on  the  main  shaft  by  means  of  a  sleeve  to  which 
both  sprockets  and  gear  are  connected.  The  gear  A  is 
alwajrs  in  engagement  with  the  gear  B  which  drives  the 
counter  shaft.    The  splined  driving  sleeve  C  is  attached 


272 


This  Modern  <1as  Tractor 


to  the  differential  gear  casing  and  is  hollow  so  that  the 
shaft  driving  the  bull  pinions  can  pass  through  it.  With 
the  sliding  clutch  D  in  the  position  indicated  the  splined 
differential  drive  shaft  C  is  locked  firmly  to  the  driving 
gear  A,  and  the  drive  is  direct  from  the  engine  to  the 
differential  casing.  The  only  reduction  of  speed  ob- 
tained is  because  of  the  varying  diameter  of  the  drive 
sprocket  on  the  transmission  and  that  on  the  engine 
crank  shaft. 

If  the  sliding  clutch  D  is  moved  over  until  the  sprocket 


BULL  PINION 
iDRIVE  SPROCKET; 

\ 


COUNTERSHAFT 

DIFFERENTIAL 
GEARING    CASE 

'and  brake 

DRUM 


Fief.  107. — View  of   Transmission   and   Differential   Unit   With 
Cover  Removed. 

on  the  differential  case  drive  shaft,  which  normally 
revolves  free  upon  it,  is  clutched  to  that  member  then  a 
reverse  motion  will  be  obtained.  The  drive  from  the 
engine  is  to  the  drive  sprocket  of  the  transmission  gear- 
ing, which  turns  in  the  same  direction  as  the  engine 
crank  shaft  and,  of  course,  carries  the  gear  A  with  it. 
The  gear  B  turns  in  a  reverse  direction  and  the  counter 
shaft  is  revolved  in  a  reverse  direction  to  that  of  the 
engine  crank  shaft.     The  splined  differential  drive  shaft 


The  Modern  Gas  Tractor 


273 


SLIDING  GEAR 


COUNTERSHAFT 


Fig.  108. — View  of   Change   Speed   Gearing  of   I.    H.    C.    Two 
Speed  Tractor  With  Sliding  Gear  in  Neutral  Position. 

C  is  now  free  to  turn  inside  of  gear  A  and  is  driven  in 
the  same  direction  as  the  counter  shaft  by  means  of  the 
driving  chain,  which  now  imparts  motion  from  the  coun- 
ter shaft  to  the  splined  differential  case  drive  sleeve  C. 
The  bull  pinions  which  are  driven  from  the  differential 
gear  are  now  turning  in  a  direction  opposite  to  that  of 
the  engine  crank  shaft. 

In  order  to  obtain  the  high  speed  the  sliding  clutch  D 


21  ± 


The  Modern  Gas  Tractor 


SUD/NG    GEAR 


Fig.  109.— Sliding  Gear  of  I.  H.   C.  Two  Speed  Transmission 
in  Low  Speed  Position. 

is  placed  in  a  neutral  position  so  that  it  is  out  of  mesh 
with  either  gear  A  or  the  reverse  sprocket.  The  sliding 
gear  E  which  is  keyed  to  the  differential  drive  sleeve  C 
is  then  slid  into  mesh  with  the  gear  F  on  the  counter 
shaft.  The  drive  from  the  engine  to  the  drive  sprocket 
turns  the  gear  A  in  the  same  direction  as  the  engine 
revolves.  The  counter  shaft  is  turned  in  a  reverse  direc- 
tion by  the  constant  mesh  gear  B  which  turns  E  in  the 


The  Modern  Gas  Tractor 


275 


SLIDING     GEAR 
ENGINE 


?'!i!if  ^INTERMEDIATE 
DRIVE 
GEAR 


Wlarl 


COUNTERSHAFT 


Fig.  110.— Sliding  Gear  of  I.  H.  C.  Two  Speed  Transmission 
in  Direct   Drive  Position. 

same  direction  and  at  the  same  speed  as  gear  B.  The 
direction  is  reversed  by  the  sliding  gear  E  and  the  differ- 
ential is  driven  in  the  same  direction  as  the  transmission 
drive  sprocket  but  at  a  higher  rate  of  speed  on  account 
of  the  difference  in  size  between  gear  F  and  sliding  gear 
E.  The  reason  that  the  highest  speed  is  obtained  through 
gearing  instead  of  on  the  direct  drive  is  because  it  is 
desirable  to  do  the  heavy  work  through  as  few  gears  as 
possible  because  each  set  of  gears  in  mesh  increases  the 


l»7(i  The  Modern  Gas  Tractor 

friction  and  decreases  the  efficiency  of  the  drive.  The 
lowest  speed  forward  in  this  transmission  is  the  one  on 
which  heavy  work  such  as  ploughing  and  breaking  will 
be  done,  and  more  of  the  engine  power  is  available  than 
would  be  the  case  if  there  was  an  added  loss  through 
another  pair  of  gears. 

A  simple  sliding  gear  utilized  on  the  I.  H.  C.  two- 
speed  tractors  is  shown  at  Figs.  108  to  110  inclusive. 
In  this,  the  sliding  gear  member  is  carried  on  the  engine 
shaft  in  such  a  way  that  it  may  be  engaged  with  the 
intermediate  drive  gear  either  through  the  counter 
shaft  carried  below  it  or  by  direct  connection  Avith  the 
intermediate  gear.  At  Fig.  108  the  sliding  gear  is  shown 
in  a  neutral  position.  The  gearing  on  the  cross  shaft 
cannot  turn  because  the  sliding  gear  is  not  in  mesh 
with  the  large  gear  on  the  counter  shaft.  When  the  slid- 
ing gear  is  moved  to  the  position  shown  at  Fig.  109,  the 
gearing  is  in  low  speed.  The  gear  carried  on  the  engine 
shaft  is  driving  a  larger  gear  on  the  counter  shaft  which 
in  turn  is  driving  the  intermediate  gear  through  a  small 
spur  pinion.  When  the  sliding  gear  is  moved  over  so 
that  it  is  out  of  mesh  with  the  large  gear  on  the  coun- 
ter shaft  and  engaged  directly  with  the  intermediate 
drive  gear,  the  highest  speed  ratio  is  obtained. 

The  Differential  Gear  and  Its  Use. — The  differen- 
tial gearing  is  one  of  the  most  important  parts  of  the 
gas  tractor  as  well  as  the  automobile.  This  arrange- 
ment of  gearing  permits  the  rear  wheels  to  revolve  at 
different  speeds  and  at  the  same  time  act  to  drive  the 
tractor.  When  a  tractor  turns  a  corner  the  inner  wheel 
must  revolve  slower  than  the  outer  one  because  it  is  not 
covering  as  much  ground.  The  differential  gear  makes 
this  possible  in  a  very  simple  manner.  The  construction 
of  a  typical  differential  gear  is  shown  in  outline  at  Fig. 


The  Modern  Gas  Tractor 


278  The  Modern  Gas  Tractor 

111  in  the  form  that  it  is  usually  employed  on  gas  trac- 
tors. 

In  this  application  the  differential  gear  is  mounted  on 
a  cross  shaft,  which  is  the  usual  method  of  installing  it 
on  both  gas  and  steam-propelled  traction  engines.  The 
bull  pinion  A  is  attached  to  a  continuous  shaft  which 
passes  through  the  center  of  the  differential  gearing  and 
which  is  driven  by  the  bevel  gear  A.  The  bull  pinion  B 
is  attached  to  a  sleeve  forming  part  of  bevel  gear  B  and 
can  revolve  independently  of  the  continuous  through 
shaft  when  desired.  The  differential  driving  gear,  which 
is  turned  by  the  source  of  power,  is  mounted  independent 
of  the  continuous  shaft  and  is  coupled  to  bevel  gears  A 
and  B  only  through  the  medium  of  bevel  pinions  C  and 
D,  which  are  attached  to  and  revolve  upon  studs  carried 
by  the  differential  spider. 

Assuming  that  all  the  gears  are  in  mesh,  as  outlined, 
if  the  resistance  to  traction  is  the  same  at  both  rear 
wheels  the  power  applied  at  the  differential  drive  gear 
will  be  directed  to  both  bull  pinions  A  and  B,  and  the 
entire  assembly,  which  is  comprised  of  the  differential 
spider  and  pinions  attached  to  it  and  the  bevel  gears  A 
and  B  which  drive  the  bull  pinions,  will  revolve  as  a 
unit. 

Should  the  traction  resistance  against  the  driving 
wheels  vary,  as  is  the  case  when  the  tractor  turns  a 
corner,  or  deviates  otherwise  from  a  straight  course,  so 
that  one  wheel  tends  to  revolve  faster  than  the  other, 
the  small  bevel  pinions  C  and  D  will  not  only  turn 
around  on  the  studs  on  which  they  are  mounted  but  at 
the  same  time  will  run  around  the  gears  A  and  B  because 
the  differential  spider  is  being  rotated  by  the  engine. 
When  turning  a  corner  the  other  wheel  must  revolve  so 
much  faster  than   the  inner  member  that  it  is  just  as 


The  Modern  Gas  Tractor 


279 


DRIVE  GEAR        ^  f\/\AA /W]  ^  ^    ^PINION 


DIFFERENTIAL 
SPIDER 


BEVEL 
PINION 


Fig.  112. — The    Differential    Spider    With    Bevel    Pinions   and 
Spur  Drive  Gear  Attached. 

though    one    of  the  wheels  was  held  almost  stationary 
and  the  other  turned. 

The  action  of  the  differential  pinions  may  be  clearly 
understood  by  giving  due  consideration  to  the  following 
principles:  The  same  resistance  at  the  point  of  con- 
tact between  the  driving  wheels  and  the  ground  prevents 
the  pinions  from  revolving  on  their  own  studs,  and  in 
this  case  they  act  simply  as  keying  members  between 
bevel  gears  A  and  B  and  are  carried  around  by  the  differ- 
ential spider.     If  the  resistance  upon  bull  pinion  A  is 


280 


Tiik  Moi/ern  Gas  Tractor 


greater  than  that  on  bull  pinion  B  the  differential  spider 
will  rotate  forward  with  the  wheel  offering  the  least 
resistance  and  the  differential  pinions  will  turn  on  their 
studs  and  run  over  the  surface  of  the  gear  which  tends  to 
remain  stationary,  this  obviously  being  the  one  against 
which  there  is  the  greatest  resistance.  The  differential 
pinions  can  thus  turn  independently  of  one  bevel  gear 
wheel  and  run  over  its  surface  without  turning  it  and  at 
the  same  time  act  as  clutching  members  of  sufficient 
capacity  to  carry  the  other  bevel  gear  and  the  bull  pinion 


BULL  PINION 


BEARING 


BEARING 


CONTINUOUS  SHAFT 

/ 


DIFFERENTIAL     CROSS 
SHAFT     CASTING 


BEVEL  G FAR  A 


Fig.  113. — Countershaft  With  Differential  Spider  Outlined  at 
Fig.   112  Removed. 

attached  to  it  in  the  same  direction  as  the  differential 
spider  and  at  a  ratio  of  speed  which  will  depend  upon 
the  difference  in  resistance  between  the  friction  members 
and  the  ground. 

While  the  differential  described  is  of  the  bevel-pinion 
type,  and  is  the  form  generally  used  on  gas  tractors,  the 
differential  effect  can  be  obtained  by  a  combination  of 
spur  pinions  and  spur  gears  just  as  well.  The  appear- 
ance of  the  differential  spider  and  the  manner  in  which 
the  bevel  pinions  are  carried  around  with  it  is  clearly 
outlined  at  Fig.   112.     This  also  shows  the  method  of 


The  Modern  (Jas  Tractor  L'sl 

bolting  the  drive  gear  to  the  differential  spider.  At  Fig. 
113  the  other  parts  comprising  the  differential  gear  as- 
sembly, when  the  differential  spider  shown  at  Fig.  112 
is  removed,  are  clearly  shown. 

It  is  sometimes  desirable  to  lock  the  differential  gear 
so  that  it  will  be  temporarily  out  of  commission.  This 
condition  would  be  desirable  if  one  of  the  wheels  was  in 
a  mud  hole  where  the  resistance  to  its  turning  was  slight, 
while  the  other  was  on  hard  ground  which  offered  con- 
siderable resistance  to  its  moving.  When  the  power  was 
applied  the  wheel  that  was  in  the  mud  hole  would  revolve 
without  driving  the  tractor,  as  the  difference  in  traction 
resistance  between  the  ground  and  the  two  wheels  would 
be  too  great.  If  the  two  bevel-gear  members  A  and  B 
ami  the  differential  spider  were  locked  together  by  a  bolt 
passing  through  the  three  of  them,  or  its  mechanical 
equivalent,  then  the  power  would  be  applied  to  both 
wheels  and  the  tractor  would  pull  itself  out  onto  the  firm 
road  surface  again.  Obviously,  before  attempting  to 
turn  any  corners  or  deviate  from  a  straight  path  it  would 
be  necessary  to  remove  the  locking  bolt  so  that  the  differ- 
ential could  function  properly  again. 


CHAPTER  VIII. 

THE  TRACTOR  FRAME,  WHEELS  AND  AXLES. 

Construction  of  Tractor  Frames — Typical  Frames  Described — 
Why  Three  Point  Support  is  Needed — Facts  Concerning 
Tractor  Wheels — Methods  of  Construction — Action  and 
Advantages  of  the  Caterpillar  Tread — Tractor  Front 
Axles— How  Tractors  are  Steered — Automatic  Steering 
Arrangements — Methods  of  Final  Drive — The  Conven- 
tional Method — Use  of  Chains  and  Sprockets — Live  Axle 
Forms. 

Construction    of    Tractor    Frames. — One    of   the 

important  components  of  the  modern  gas  tractor  and 
that  which  determines  whether  the  machine  will  be 
enduring  and  efficient,  is  the  frame.  This  serves  to  tie 
and  support  all  other  parts  of  the  machinery  and  is 
depended  on  to  maintain  proper  alignment  between 
the  various  components  of  the  power  generating  and 
transmission  groups.  If  the  design  of  this  foundation 
is  neglected  or  slighted  the  efficiency  of  the  tractor  will 
be  materially  reduced.  A  light,  poorly  braced  frame 
will  permit  the  various  parts  to  get  out  of  line  if  the 
tractor  is  operated  over  irregular  or  rough  surfaces, 
such  as  obtain  in  most  fields. 

The  frame  must  be  heavy  enough  to  furnish  a  substan- 
tial foundation  for  the  power  plant  as  a  frame  that  was 
inadequate  in  strength  would  produce  rapid  deterior- 
ation of  the  mechanism  because  it  would  subject  it  to 
strains  that  it  was  not  designed  to  withstand.  When 
bearings  cramp  out  of  line  much  more  power  is  con- 

282 


The  Modern  Cas  Tractor  283 

sumed  in  bearing  friction  and  this  in  turn  means  greater 
wear  of  the  components.  It  is  imperative  that  the  frame 
be  of  sufficient  size  and  have  strength  enough  to  furnish 
a  practically  vibrationless  bed  for  the  engine  and  have 
room  to  support  the  engine,  radiator,  transmission 
mechanism,  fuel  tanks,  and  operators'  platform.  In 
order  to  obtain  the  strength  that  is  desirable  in  frame 
construction  the  usual  material  employed  is  the  merchant 
structural  shapes  in  steel,  such  as  I  beams,  angles  or 
channels. 

These  members  usually  extend  from  front  to  rear  and 
join  the  axles  and  are  commonly  held  together  cross- 
wise by  other  cross  pieces  which  are  well  braced  by  liberal 
gussets  or  fish  plates.  The  frame  is  one  member  that 
will  rarely  need  replacing,  therefore  it  is  usually  a  built- 
up  structure  composed  of  members  permanently  fastened 
together  by  riveting.  The  frame  should  support  the 
bearings  to  which  the  important  members  of  the  trans- 
mission and  rear  axle  are  fastened,  and  it  is  good 
practice  to  attach  a  sub-frame  or  inner  frame  of  steel 
to  the  main  frame  for  supporting  the  engine  and  related 
parts.  Some  manufacturers  build  up  the  frame  of  steel 
plates  firmly  riveted  together  and  following  bridge  con- 
struction in  that  the  area  of  the  section  is  greatest  at 
the  point  farthest  away  from  the  supports.  Tractor 
frames  are  sometimes  built  up  of  two  main  castings,  one 
at  the  front,  the  other  at  the  rear,  joined  by  channels  or 
steel  angles.  The  front  casting  serves  as  a  point  of 
attachment  for  the  front  axle,  while  the  rear  member  is 
often  employed  to  support  the  important  shafts  and  bear- 
ings. 

Typical  Frames  Described. — A  typical  tractor 
frame  from  which  the  power  plant  and  related  parts  has 
been  removed  is  shown  at  Fig.  114.     It  will  be  seen  that 


284 


The  Modern  Gas  Tractor 


Thk  Modern  Gas  Tractor  285 

the  frame  proper  is  composed  of  steel  channels,  which  are 
firmly  attached  together  by  bolts.  A  sub-frame  is  car- 
ried beneath  the  main  frame  and  forms  a  support  for  the 
power  plant.  The  important  parts  of  the  transmission 
mechanism  are  clearly  shown  as  is  the  general  construc- 
tion of  the  front  and  rear  wheels  and  steering  mechan- 
ism. The  frame  shown  at  Fig.  115  is  one  from  which 
the  wheels  have  been  removed  and  shows  clearly  the 
method  of  construction  ordinarily  followed  on  tractors 
of  conventional  design.  The  frame  consists  of  two  side 
members  cambered  in  at  the  front  at  a  point  just  for- 
ward of  the  steering  gear,  which  are  joined  together  by 
means  of  cross  braces  of  steel  channels,  angles,  and  plain 
bar  stock.  The  engine  is  located  just  forward  of  the 
intermediate  drive  gear  and  is  arranged  in  such  a  way 
that  this  member  meshes  with  a  gear  on  the  engine 
crank  shaft.  The  change  speed  and  reverse  gearing  are 
thoroughly  encased  and  form  a  unit  with  the  differential 
cross  shaft,  which  carries  the  bull  pinions  which  drive 
the  rear  wheels  through  the  medium  of  the  bull  gears. 
The  operator's  platform  and  the  drawbar  to  which  the 
ploughs  or  other  machinery  are  attached  are  also  clearly 
shown  at  the  rear  end  of  the  machine. 

The  method  of  using  a  casting  for  the  rear  end  of  the 
tractor  frame  and  the  advantages  of  this  construction 
are  clearly  illustrated  at  Fig.  116.  It  will  be  observed 
that  the  counter  shaft  and  rear  axle  are  carried  in  sub- 
stantial cast  frame  members  which  are  attached  to  the 
side  channels  very  securely.  As  the  boxes  which  serve 
as  bearings  for  the  counter  shaft  and  rear  axle  form  part 
of  the  same  casting  member  it  will  be  apparent  that  a 
very  stiff  construction  that  will  prevent  frame  distortion 
is  utilized  to  secure  the  advantages  accruing  from  abso- 
lute alinement  of  driving  and  driven  members. 


286 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor 


2S7 


Fig.  115a.— Frame  of  the  "Twin  City  40"  Gas  Tractor  Built 
of  Standard  Structural  Shapes,  Such  as  Angles  and  Chan- 
nels Joined  Together  by  Flat  Bars  and  Braced  by  Plates. 
An  Exceptionally  Substantial  Design  Representative  of 
Best  Construction. 

Why  Three=point  Support  Is  Needed. — The  aver- 
age traction  engine  is  designed  for  rough  service  and  is 
often   operated   under   conditions   where   a   more   finely 


288 


Tin:  Modern  Gas  Tractor 


constructed  piece  of  machinery  would  soon  be  ruined. 
The  fields  in  which  tractors  are  operated  are  full  of  hol- 
lows and  hummocks  and  in  order  to  be  practical  the  trac- 
tor frame  should  be  mounted  in  such  a  way  that  it  will 
be  able  to  tilt  when  one  of  the  wheels  is  lower  or  higher 
than  its  mate,  without  stressing  the  frame  side  members 
and  imposing  strains  on  the  mechanism.  The  three- 
point  method  of  support  is  the  simplest  way  of  accom- 


STEEL    CHANNEL 


COUNTERSHAFT 


Fig.  116.— Rear  End  of  I.  H.  C.  Tractor  Frame,  Showing 
Substantial  Cast  Members  Serving  to  Support  Counter- 
shaft and   Rear  Axle  Bearings. 

plishing  this  end.  With  a  three-wheel  tractor  a  three- 
point  support  is  obtained  by  the  arrangement  of  the 
supporting  members,  but  when  four  wheels  arc  utilized 
it  is  necessary  to  design  the  tractor  so  that  it  can  tilt 
without  throwing  the  machinery  out  of  line.  This 
means  that  the  entire  frame  must  move  as  a  rigid  unit 
without  appreciable  distortion. 


The  Modern  Gas  Tractor 


289 


LM.M i  The  Modern  Gas  Tractor 

Owing  to  the  method  of  drive  employed  on  most  trac- 
tors of  the  conventional  pattern  it  is  not  possible  to 
have  the  rear  axle  movable  relative  to  the  frame  struc- 
ture. It  is  therefore  the  rule  to  arrange  the  front  axle 
so  that  it  will  be  supported  or  pivoted  at  one  point  at 
its  center  to  permit  the  frame  to  tilt  as  conditions  dic- 
tate. The  two  views  at  Fig.  117  outline  the  method  of 
attaching  the  swinging  front  axle  to  the  frame  so  that  it 
may  move  with  minimum  friction  when  operated  to 
steer  the  tractor  and  at  the  same  time  permit  the  frame 
to  tilt.  The  view  at  A  shows  the  front  end  of  the  tractor 
with  the  frame  level,  which  condition  obtains  when  the 
tractor  is  operated  on  a  comparatively  smooth  surface. 
At  B  one  of  the  rear  wheels  of  the  tractor  has  been 
blocked  up  in  such  a  way  that  it  is  a  foot  or  more  higher 
than  the  one  on  the  opposite  side.  It  will  be  evident 
that  the  entire  frame  and  mechanism  has  tilted  over  to 
one  side  on  the  single  point  of  support  over  the  front 
axle,  while  that  member  remains  level.  Obviously,  the 
conditions  may  be  reversed,  the  rear  wheels  being  on  an 
even  plane  and  the  frame  level,  but  the  front  axle  tilted 
at  an  angle  as  will  be  the  case  if  one  of  the  front  wheels 
was  passing  over  an  obstacle.  ■"> 

Three-point  support  is  not  difficult  to  obtain  when 
the  one-piece  swinging  front  axle  is  utilized  because  a 
pivoted  point  is  necessary  to  secure  easy  steering.  When 
the  Ackerman  type  axle  is  used,  however,  this  being 
the  form  in  which  the  wheels  are  carried  by  steering 
knuckles,  it  would  not  be  necessary  to  supply  the  single 
pivotal  point  of  support  if  it  were  not  imperative  to  have 
the  three-point  method  of  suspension.  Fig.  118  outlines 
the  construction  of  a  skeleton  type  movable  spindle  axle 
which  is  hinged  at  a  central  point  to  permit  the  front 
wheels  to  tilt  as  indicated  in  the  illustration. 


The  Modern  Gas  Tractor 


12!)  1 


PIVOT 


Fig.  118. — Showing  Arrangement  of  Ackerman   Front   Axle   to 
Obtain   Three  Point  Support  of  Tractor  Frame. 

Gas  tractors,  as  a  rule,  are  not  mounted  on  springs 
because  their  speed  of  travel  is  slow  and  the  large  wheels 
employed  reduce  the  need  for  springs  which  are  so  neces- 
sary with  automobiles  or  horse-drawn  vehicles.  The 
front  view  of  a  Phoenix  tractor  outlined  at  Fig.  119  shows 
the  method  of  utilizing  a  spring  mounting  for  the  front 
axle  and  at  the  same  time  obtaining  the  desired  degree 
of  flexibility  essential  to  a  practical  three-point  support 
running  gear.    Two  springs  are  used,  one  at  each  side  of 


2!>° 


The  Modern  Gas  Tractor 


£  *§?. 


W&Bx&Et 


Fig.  119. — Method  of  Mounting  Front  End  of  Phoenix  Tractor 
Frame  on  Springs  Designed  to  Permit  Three  Point  Sus- 
pension Principle. 

the  axle,  and  these  carry  a  bearing  at  their  center  which 
rocks  on  a  stud  attached  to  the  bottom  of  the  curved 


The  Modern  Gas  Tractor 


293 


front  frame  member.  The  construction  is  so  clearly 
shown  in  illustration  that  further  description  is  unneces- 
sary. 

Facts  Concerning  Tractor  Wheels. — Gas  tractor 
frames  may  be  mounted  on  either  three  or  four  wheels. 
When  a  three-wheel  construction  is  employed  it  is  some- 
times the  two  front  wheels  that  are  used  for  steering  with 
a  single  large  driving  member  and  in  some  cases  the  two 
front  wheels  serve  as  driving  members  while  a  single 


Fig.  120. — Showing  Advantages  of   Large   Wheels  for  Tractor 
Driving  Members. 

rear  wheel  serves  to  steer  the  vehicle.  The  four-wheel 
construction  is  the  most  conventional,  however,  and  the 
two  front  wheels  are  smaller  in  diameter  and  much 
lighter  than  the  rear  wheels  and  are  used  practically 
only  for  steering  purposes  as  most  of  the  tractor  weight, 
in  some  cases  80  or  90  per  cent,  is  carried  over  the  rear 
or  traction  members.  When  a  single  rear  driving  wheel 
is  employed  no  differential  gear  is  needed,  though  most 
engineers  prefer  to  use  two  traction  members  and  obtain 


2i>4  The  Modern  Gas  Tractor 

a  more  effective  contact  area  between  driving  members 
and  the  ground.  The  front  wheels  are  generally  of  the 
same  type  and  are  a  built-up  structure  composed  of  a 
hub  from  which  circular  section  spokes  of  steel  rod 
radiate  to  the  steel  rim.  Generally  a  raised  collar  or 
flange  is  shrunk  onto  the  smooth  tire  to  prevent  side 
slip.  In  some  cases  the  wheels  are  made  in  one  piece 
and  have  the  rim,  spokes  and  hub  cast  integral. 

The  traction  wheels  vary  from  twenty  to  thirty-two 
inches  wide  and  from  six  to  eight  feet  in  diameter.  Most 
engineers  favor  a  large  wheel  because  this  will  bridge  over 
irregularities  of  the  field  surface  easier  than  the  wheels 
of  lesser  diameter,  have  more  area  of  contact  with  the 
ground  and  are  much  more  efficient  as  driving  mem- 
bers. The  advantages  when  a  large  wheel  is  used  com- 
pared to  one  of  smaller  diameter  under  similar  condi- 
tions are  clearly  outlined  at  Fig.  120.  In  this  case  it  is 
assumed  that  each  wheel  has  sunk  six  inches  into  the 
ground.  It  will  be  noted  that  the  area  of  contact  of  the 
6-foot  diameter  wheel  is  but  5.8  square  feet  while  that 
of  the  8-foot  diameter  member  is  7.75  square  feet.  In 
order  to  pull  the  tractor  out  of  the  rut  the  engine  must 
exert  as  much  power  with  a  6-foot  wheel  as  would  be 
necessary  to  pull  it  up  a  66  per  cent  grade.  With  the 
8-foot  wheel  the  amount  o  angularity  is  reduced  and  the 
grade  corresponds  to  but  55  per  cent.  It  will  be  evident 
by  study  of  diagram  why  the  large  wheel  is  superior  to 
the  member  of  less  diameter. 

Methods  of  Construction. — The  best  driving  wheel 
construction  is  known  as  the  built-up  type  of  wheel 
which  is  l'ghter  than  the  cast  wheel  and  which  has 
ample  strength  when  properly  designed  to  do  the  work. 
There  are  two  general  methods  of  construction  used 
in   the   built-up   type   of   wheels.      In   one,   spokes   are 


The  Modern  Gas  Tractor 


295 


GEAR   WHEEL 
SPOKES     ■ 


TRANSMISSION 
BAR 


EXTERNAL  SPUR  GEAR 


Fig.  121. — Tractor  Driving  Wheel  Showing  Method  of  Attach- 
ing External  Spur  Bull  Gear  to  Wheel  Hub  and  Rim. 

made  of  flat  bars  which  are  bent  over  and  riveted  to 
the  rim  of  the  driver.  Each  spoke  is  attached  to  the 
hub  by  rivets  and  the  weight  of  the  engine  is  carried 
by  subjecting  the  spokes  to  a  compress  on  stress,  such 
as  obtains  on  practically  all  types  of  horse-drawn 
vehicles.  .  The  other  and  preferred  construction  is 
known  as  "the  suspended  type"  of  wheel.  The  spokes 
have  round  heads  and  pass  completely  through  the 
rims  and  are  attached  to  the  hub  in  much  the  same 
manner  as  a  wire  spoke  bicycle  or  automobile  wheel. 


29G  The  Modern  Gas  Tractor 

The  weight  of  the  tractor  is  therefore  suspended  by 
the  spokes  which  are  under  tension  instead  of  compres- 
sion. With  this  method  of  construction  there  are  no 
rivets  to  shear  off  and  get  loose  and  the  suspended 
type  of  wheel  is  not  only  considerably  lighter  than  the 
flat  spoke  type  but  it  has  greater  resiliency  and  is 
superior  to  either  the  cast  or  flat  spoke  type  of  wheels 
for  this  reason 

In  order  to  make  a  large  driving  wheel  practical 
when  of  the  built-up  type,  it  is  desirable  to  remove 
all  driving  strains  from  the  spokes,  and  in  order  to 
accomplish  this  the  power  that  is  applied  to  the  large 
master  gears  is  transmitted  to  the  rim  directly  by  con- 
necting the  driving  gear  to  the  steel  plate  rim  member 
by  bars  of  flat  or  round  stock.  The  rims  of  the  wheels 
must  be  of  sufficient  strength  to  withstand  hard  usage 
and  are  nearly  always  reinforced  to  prevent  crimping. 
This  reinforcement  may  be  angle  iron  or  channel  iron 
hoops  riveted  to  the  inner  periphery  of  the  wheel  or 
the  rims  may  be  specially  rolled  so  as  to  have  an  in- 
wardly projecting  flange  so  that  the  rim  will  be  suitably 
reinforced  and  at  the  same  time  retain  the  advantages 
of  one  piece  construction. 

A  typical  traction  whee  of  the  suspension  spoke 
type  is  shown  at  Fig.  121.  The  master  driving  gear 
or  bull  gear,  as  it  is  generally  called,  is  centered  from 
the  wheel  hub  by  means  of  five  rods,  spaced  equidistantly 
around  its  circumference  and  provided  with  adjustable 
members  which  make  for  accurate  gear  location.  The 
actual  driving  strains  are  taken  from  the  gear  rim  by 
means  of  the  four  brackets  of  flat  stock  which  are 
attached  to  the  driving  gear  at  one  point  and  to  the 
rim  of  the  wheel  at  two  points.  The  wheel  at  Fig.  122 
is  practically  the  same  in  construction,  except  that  the 


The  Modern  Gas  Tractor 


297 


driving  gear  is  an  internal  spur  form  and  has  spokes 
cast  with  the  gear  rim.  The  casting  emploj'ed  for  the 
hub  is  also  shown.  The  holes  in  the  outer  periphery- 
are  used  to  pass  the  spokes  through  while  the  series 
of  slotted  openings  in  the  flanges  of  the  hub  permit 
the  assembler  to  insert  nuts  which  hold  the  spokes 
under  tension  and  insure  firm  attachment  to  the  hub. 


TRANSMISSION    BAR 


TERNAL  SPUR 
GEAR 


HUB  CASTING 


Fig.  122. — Tractor  Driving  Wheel  and  Hub  Casting.  Note 
Internal  Spur  Drive  Gear  and  Method  of  Attaching  to 
Hub   and   Rim. 

On  some  forms  of  tractors  it  is  considered  desirable 
to  reduce  the  shock  of  driving  as  much  as  possible  by 
connecting  the  driving  gear  to  the  wheel  rim  by  trans- 
mission rods  and  springs  instead  of  the  stiffer  bars 
previously  described.  The  wheel  shown  at  Fig.  123 
is   a  flat  spoke  form.     The  master  driving  gear  is  at- 


298 


The  Modern  Gas  Tractor 


t ached  to  a  series  of  five  lugs  which  deliver  their  power 
to  the  wheel  rim  through  the  medium  of  transmission 
rods,  which  are  joined  to  the  movable  lugs  only  by 
means  of  helical  coil  springs.  The  drive  is  thus  directed 
to  the  wheel  rim  by  yielding  members  and  the  wheel 
is  not  subjected  to  shocks  which  may  result  from  irregu- 
lar or  sudden  power  application  to  fixed  gearing.  This 
also  permits  the  wheel  to  surmount  obstacles  without 
producing   as   much   strain   on   the   transmission   gears 


FLAT    SPOKE 


TRANSMISSION 
ROD 


LUG  TO  WHICH 
DRIVING     GEAR   15 

FASTENED 


Fig.  123.— Traction  Wheel  of  Gas  Tractor  With  Spring  Mem- 
bers to  Remove  Shocks  From  Driving  Gears. 


The  Modern  Gas  Tractor 


299 


Fig.  124. — Driving   Wheel   of   Tractor   Utilizing   Chain   Drive. 

as  would  obtain  if  the  bull  gear  was  attached  directly 
to  the  wheel  rim  by  non-yielding  transmission  rods. 

The  wheel  depicted  at  Fig.  124  differs  from  those 
previously  shown  in  that  it  is  provided  with  a  driving 
sprocket  instead  of  a  spur  gear  and  must  be  operated 
through  the  medium  of  chains  instead  of  by  direct 
meshing  of  teeth,  as  is  the  case  with  either  internal  or 
external  spur  gear  drive. 


300 


The  Modern  Gas  Tractor 


A  typical  hub  is  shown  in  section  at  Fig.  125.  This 
consists  of  a  casting  pierced  with  a  number  of  holes 
through  which  the  spokes  extend  to  the  rim.  This 
hub  is  of  steel  and  is  lined  with  a  bushing  of  bronze 
which  is  interposed  between  it  and  the  steel  shaft  and 
well  lubricated  to  take  the  wear.  It  is  kept  from  end 
movement  by  means  of  a  bronze  thrust  collar,  which 
bears  against  the  axle  supporting  bearing  and  the  face 
of  the  hub  flange.  The  hub  is  prevented  from  coming 
off  by  a  dust  collar  which  is  pinned  to  the  axle. 


Fig.  125. — Cross    Section    of    Hart-Parr    Rear    Hub    Showing 
Wheel  Bearing  and  Method  of  Lubrication. 

In  order  to  secure  greater  traction  on  soft  ground 
than  would  be  obtainable  with  a  smooth  steel  tire  the 
outer  rims  of  the  traction  wheels  are  always  provided 
with  a  series  of  projecting  lugs  or  points  which  are 
called  "grouters."  These  may  be  of  pressed  steel, 
steel  castings,  malleable  or  cast  iron.  They  are  some- 
times attached  parallel  to  the  axle  and  at  other  times 
at  an  angle  to  facilitate  self-cleaning.      When  grouters 


The  Modern  Gas  Tractor 


301 


are  set  at  an  angle  they  are  generally  placed  so  that 
the  rear  end  of  one  comes  opposite  the  front  of  the 
adjacent  member  so  the  circumference  of  the  wheel 
is  made  more  continuous  and  jolting  is  eliminated  on 
hard  surfaces.  Pressed  steel  plates  may  be  used  to 
form    a    continuous    succession    of    corrugations    which 


Fig.  126. — Traction  Wheel  Rims  Showing  Cleats  or  Grouters 
of  Various  Types  Utilized  to  Increase  Frictional  Adhesion 
With  Ground. 

will  extend  entirely  around  the  circumference  of  the 
wheel.  It  is  claimed  that  this  form  of  construction 
can  pass  over  soft  ground  without  tearing  up  the  sur- 
face and  at  the  same  time  it  is  as  efficient  under  other 
conditions   as   the   other   types.      Some   tractor   manu- 


302 


The  Modern  Gas  Tractor 


facturers  provide  sharp  conical  pyramid  shape  spikes 
which  may  be  removed  if  the  tractor  is  to  be  operated 
over  road  surfaces  that  it  is  not  desirable  to  tear  up. 
Various  forms  of  grouters  are  shown  at  Fig.  126. 
Those  outlined  at  A  are  merely  strips  cut  from  T  section 
iron  bar  riveted  to  the  wheel  rim.  This  is  the  form 
usually  provided  on  English  tractors  and  while  these 
prove  very  efficient  on  good  roads  they  are  not  as  satis- 
factory as  the  more  pronounced  grouters  or  mud  lugs 


Fig.  127. — Extension  Rims  Designed  to  be  Attached  to  Regular 
Traction  Wheels  to  Obtain  Greater  Contact  Area  When 
Used   on   Soft   Ground. 

in  general  field  work.  The  grouters  shown  at  B  are 
iron  castings  bolted  to  the  rim.  At  C  a  combination 
of  angularly  placed  grouters  and  external  flanges  to 
minimize  lateral  slip  of  the  wheel  is  provided.  It  is 
sometimes  desirable  to  provide  a  greater  area  of  con- 
tact than  is  obtained  with  the  regular  width  wheel 
when  operating  a  tractor  on  soft  ground.  Extension 
rims,  such  as  shown  at  Fig.  127,  are  provided  in  most 


The  Modern  Gas  Tractor 


303 


cases  for  use  in  conjunction  with  the  regular  types 
of  wheels.  These  extensions  range  from  ten  to  fifteen 
inches  in  width  and  are  designed  so  that  they  may  be 
easily  attached  to  the  traction  members  when  it  is 
desired  to  increase  the  width  of  the  wheels. 

Action  and  Advantages  of  the  Caterpillar  Tread. 
— It  is  a  fact  that  will  not  be  questioned  that  a  heavier 
load  can  be  hauled  over  a  smooth  road  than  over  a 
rough  or  muddy  one.  The  locomotive,  a  very  efficient 
and  powerful  traction  engine,  travels  on  a  smooth  steel 


Fig.  128. — Showing  Construction  of  Caterpillar  Tread  Traction 
Member  of  Holt  Tractor. 

track.  It  would  not  be  possible  to  lay  tracks  over  our 
highways  for  tractors  to  operate  on  so  one  tractor  manu- 
facturer obtains  the  advantages  of  the  track  principle 
and  applies  it  to  the  agricultural  and  freighting  industry 
by  using  what  are  known  as  "Caterpillar  Traction 
Members."  This  tractor,  which  has  been  previously 
illustrated,  automatically  lays  and  travels  on  a  smooth 
level  steel  track,  strong,  durable  and  flexible,  over 
which  it  successfully  negotiates  ploughed  fields,  soft 
delta  lands,  prairies,  country  and  mountain  roads,  and 


304  The  Modern  Gas  Tractor 

operates  successfully  over  field  and  highway  surfaces 
that  are  very  difficult  to  negotiate  with  wheel  traction 
engines.  The  Caterpillar  Tread  enables  the  engine  to 
bridge  ditches  several  feet  in  width,  a  feat  that  is  not 
possible  with  the  wheel  forms. 

By  means  of  the  track  distribution  of  weight  is  effected 
over  an  area  of  ground   the    equal  of  which  is  not  cov- 
ered under  any  other  than  this  track  laying  principle 
of  construction.    The  increased  area  of  contact  between 
the   traction   members   and   the    ground    means   better 
traction    and    increased    drawbar     horse-power.       The 
side  view  of  the  Caterpillar  Tractor  shown  at  Fig.  16 
indicates  clearly  the  method  of  construction,  while  the 
illustration  at   Fig.    17   shows  the  tractor  from  another 
point  of  view.    The  construction  of  the  Caterpillar  trac- 
tion member  itself  is  clearly  shown  at  Fig.   128.     The 
construction    is    simple    and    easily    understood.     The 
track  shoes,   which   come  in   contact  with  the  ground 
and  take  the  place  of  a  tire  on  the  ordinary  wheel,  are 
drop    forged    from    plough    steel,    and    are    practically 
indestructible.     The  track  rails  are  made  of  steel  cast- 
ings which  have  great  strength  and  endurance.     The 
spacing  blocks  which  hold  the  pair  of  rails  to  the  proper 
distance    and   with   whicn   the   sprocket   teeth   engage 
to  drive  the  track  are  made  of  manganese  steel.     The 
power  is  applied  by  steel  sprocket  wheels  at  the  rear  end 
of  the  machine  which  continually  picks  up  the  tracks, 
carrying  them  forward   over  the  supporting  rollers  to 
blank  sprockets  which  continually  lay  the  tracks  down 
and  provide  a  path  over  which  the  engine  moves. 

The  ordinary  wheel  with  a  24-inch  base  width  in  order 
to  cover  an  area  equal  to  that  of  one  24-inch  Caterpillar 
track  would  have  to  be  120  feet  in  diameter  and  would 
weigh  more  than  fifteen  tons.     Obviously,   this  is  not 


The  Modern  Gas  Tractor 


305 


a  practical  construction,  so  the  advantage  the  Cater- 
pillar track  offers  in  the  matter  of  contact  area  in  pro- 
portion to  weight  can  be  readily  understood.  Reference 
to  the  illustration  at  Fig.  129  serves  to  bring  out  these 
differences  clearly,  while  the  tabular  comparison  at 
Fig.  130  shows  the  claims  of  the  manufacturers  of  this 
device  and  the  comparison  made  by  them  between  the 


Fig.  129. — Comparison  Between  Wheel  and  Caterpillar  Tread 
Traction  Members. 


306 


The  Modern  Gas  Tractor 


Cor~v=>*>mson     of     C^TCFff^iuLf^ff   f?rvo    VJmetel.    Tvf>£z 


Cfl TEfT P/i-L  RFf 


Wm£-£TL. 


f?e///nO-      FricttOrt 


Quite     constant  under 
Ordinary     conditions 


Very  h'ari 
eor/h 


Ground     Slippoae. 
(  Proportiona/  fo  area  of 

O-notrnc/  contact,  Wt.  on  driver^ 
One/ number  of    orovdmri 
try  confacf  v*/fh  ground 


UOOO  so.  m.  pr-our>d 
Surface     area 


Dopendenf  on  conditio 
of  pro-end .     A/ ever 
*cee  ds  3QO  stf  i  n 


f7as>um  inn     we*n>fif   on    drivers    the    same 
/m%S&Q/bs     or    more 


/  26  rcisde  r  j 


/  ood  per  so  in     ef 
around  *urfBce-&S7bz 


f^aou/fy   for  Bridoiip 
uneven    p/oces 


&Ood  on  account 
of  /onp  ground 
ConVo&f, 


\/Jo/pSrf    on  f'r-or,  t 

Sfeer/'na   Whee/s 


"Pr-acf/caffy 

con  9  fc/n  f 


7e>*refe>ncy  fa  poc^t  ffre. 
**ar^A      depend*  ~f     u^ort 
W/   per-     5a- /n.    tjnofer- 


STS"fb9.  per-    Sa- 


f/ever  mere  then    3 


■40  fo  90  fbs 


Oepen  den  t  en  7rac  fi  ve. 
e  fforf  and  pr-ades 


4o  fo  90  /is   p* 
a9.  ,„ 


Confer    of    Serosa 
er&ow  frr-Ouncf 


r^boutf   *?€>' 


Fig.  130. — Tabular  Comparison  Between  Caterpillar  and  Wheel 
Types  of  Traction  Engines. 

Caterpillar  Tread  and  the  wheel  form  that  they  also 
manufacture.  It  is  contended  that  the  great  bearing 
surface  obtained  by  this  construction  ranges  from  2,000 
to  3,600  square  inches,  varying  with  the  width  of  the 
track.  Consequently  the  weight  of  the  traction  engine 
is  so  distributed  that  a  pressure  of  but  from  four  and 
one  half  to  eight  pounds  per  square  inch  is  exerted 
against  the  ground  which  is  much  less  than  the  pressure 
exerted  by  a  horse. 

The   distribution   of   the   weight   over   such   a   great 
surface  eliminates  the  possibility  of  the  engine  becoming 


The  Modern  Gas  Tractor 


308  The  Modern  Gas  Tractor 

mired  where  the  ground  is  wet  and  soft  and  the  tractor 
cannot  pack  the  soil  and  injure  its  fertility  as  much  as 
other  forms  which  concentrate  a  greater  amount  of 
weight  on  a  lesser  bearing  surface.  The  wheel  trucks 
are  spring  mounted  and  pivot  on  center  in  order  to  per- 
mit the  tread  or  track  to  conform  with  the  irregularities 
of  the  road  bed.  Thus  the  weight  of  the  engine  is 
carried  on  eight  small  truck  wheels,  four  on  each  side, 
which  are  mounted  on  roller  bearings  to  reduce  the 
friction  and  which  roll  smoothly  along  on  the  track 
rails  like  the  truck  wheels  of  a  railroad  locomotive. 
The  combined  width  of  these  rails  is  nine  inches,  which 
is  equivalent  to  four  ordinary  sixty-pound  railroad 
rails,  two  of  which  would  have  ample  carrying  power 
to  support  the  entire  weight  of  the  Caterpi.lar  tractor. 
Tractor  Front  Axles. — The  function  of  the  tractor 
front  axle  is  more  in  directing  the  machine  than  in 
supporting  much  of  the  weight  of  the  engine.  Owing 
to  the  comparatively  small  diameter  and  width  of 
the  front  wheels  it  is  not  desirable  that  they  be  called 
upon  to  take  much  weight.  It  is  desirable  to  concentrate 
as  much  of  the  weight  on  the  rear  or  traction  members 
as  is  possible  because  the  tractive  efficiency  depends 
upon  the  amount  of  force  with  which  the  driving  mem- 
bers are  held  in  contact  with  the  ground.  Then,  again, 
if  the  front  wheels  of  a  tractor  were  called  upon  to  carry 
much  of  the  weight  it  would  be  difficult  to  control 
the  engine  when  on  soft  ground.  The  type  of  front 
axle  used  will  depend  entirely  upon  the  method  of 
steering  employed.  It  may  be  a  one-piece  axle  like 
that  of  a  carriage  or  wagon,  supported  by  a  ball  and 
socket  joint  at  the  center  which  will  permit  it  to  swivel 
around  when  operated  by  the  steering  gear  or  move 
up  and  down  under  the  influence  of  road  irregularity. 


The  Modern  Gas  Tractor 


309 


The  front  axles  of  many  tractors  follow  automobile 
engineering  principles  and  are  built  on  the  same  plan 
as  the  Ackerman  axle  so  widely  used  and  practically 
universal    on   self-propelled    road  vehicles. 


-STEERING    WHEEL 


F[G.  132.— Front  View  of  L  H.  C.  "Mogul"  Gas  Tractor  Frame 
Showing  Centrally  Pivoted  One  Piece  Axle. 

How  Tractors  are  Steered. — The  common  methods 
of  steering  tractors  when  two  front  wheels  are  employed 
are  clearly  outlined  at  Fig.  131.  At  A  the  ordinary 
tight  and  loose  chain  and  drum  construction  which  has 
received    wide    application   on   road   rollers   and    steam 


310 


The  Modern  Gas  Tractor 


\ 

ACKERMAN  TYPE 
FRONT     AXLE. 


ELLIOT 

TYPE 
STEERING 
KNUCKLE 


Fig.   133. — Front  View  of  I.  H.  C.  Tractor   Using  Ackerman 
Type  Front  Axle  With  Elliot  Pattern  Steering  Knuckles. 

traction  engines  is  outlined.  A  drum  is  mounted  across 
the  two  frame  members  and  is  operated  by  means  of 
a  worm  and  worm  wheel.  The  chains,  which  run  to 
the  front  axle  pivoted  at  a  central  point,  are  so  joined 
to  the  drum  that  when  this  is  turned  one  chain  winds 


The  Modern  Gas  Tractor  311 

up,  while  the  other  unwinds.  Obviously  the  axle  will 
be  pulled  along  with  the  chain  that  is  winding  up  and 
the  axle  and  wheel  assembly  will  assume  a  steering 
angle  just  as  the  front  wheels  of  a  horse-drawn  vehicle 
do 

The  method  at  B  is  by  the  Ackerman  axle.  The 
axle  is  a  member  fixed  in  one  direction,  i.  e.,  it  cannot 
swing  around  but  can  move  only  up  and  down  or  tip 
from  side  to  side  under  the  influence  of  hollows  or 
mounds  on  the  road  or  field  surface.  The  wheels  are 
mounted  on  small  stub  axles  which  are  attached  to 
steering  knuckles  adapted  to  swing  in  yokes  carried 
at  the  extremities  of  the  axle.  Steering  arms  extend 
from  each  knuckle  or  steering  spindle  and  are  joined 
together  by  a  tiebar  so  that  one  wheel  cannot  move 
without  producing  a  corresponding  movement  of  its 
neighbor.  One  of  the  steering  knuckles  is  provided 
with  two  steering  arms,  one  of  which  is  attached  to 
the  tiebar,  while  the  other  is  joined  to  the  steering 
mechanism  by  a  drag  link.  The  reduction  in  practic- 
ally all  cases  between  the  handwheel  and  the  steering 
members  is  by  worm  and  sector  gearing.  The  sector 
is  fulcrumed  so  that  it  swings  about  a  fixed  point  and 
the  reciprocating  motion  of  the  steering  arm  the  sector 
operates  is  transmitted  to  the  steering  knuckles  by 
the  drag  link.  The  advantage  of  the  type  of  steering 
gear  shown  at  B  is  that  it  makes  for  more  stable  sup- 
port than  the  swinging  front  axle  does  and  it  is  also 
operated  more   easily. 

The  view  at  Fig.  132  is  taken  from  the  front  end 
of  a  tractor  running  gear  and  clearly  shows  the  appli- 
cation of  the  pivoted  axle  and  the  tight  and  loose  chain 
steering  gear.  At  Fig.  133  a  heavy  tractor  front  axle 
of  the   Ackerman  type  having   Elliot   pattern   steering 


312 


The  Modern  Gas  Tractor 


^STEERING  WHEEL 


STEERING   , 
COLUMN 


DRAG 
LINK 


SINGLE  WHEEL 
f0F?  STEERING 


Fig.  134. — Front  View  of  Three  Wheel  Hart-Parr  Gas  Tractor 
Frame    Utilizing    One    Wheel    for    Steering   Purposes. 

knuckles  to  which  the  wheels  are  attached  is  clearly 
depicted.  In  a  number  of  cases  the  tractor  frame  is 
supported    by    three    wheels,    the    member    carried    at 


The  Modern  Gas  Tractor 


313 


Fig.  135.— Sectional  View  of  Front  Wheel  of  Hart-Parr  Three 
Wheel  Tractor  Showiag  Method  of  Supporting  Steering 
Member. 

the  front  end  being  utilized  for  steering.  A  frame  of 
this  pattern  is  shown  at  Fig.  134,  the  wheel  being 
op?rated  through  the  usual  form  of  steering  wheel 
by  means  of  reduction  gearing  and  a  drag  link. 


314  The  Modern  Gas  Tractor 

The  method  of  supporting  a  single  front  steering  wheel 
is  clearly  shown  at  Fig.  135.  The  wheel  has  a  large 
hub  which  is  provided  with  a  bearing  surface  on  its 
inner  periphery  which  runs  on  two  bronze  bushings 
carried  by  the  steering  knuckle.  The  wheel  is  supported 
by  a  cross  member  which  is  attached  to  a  bearing  in 
which  the  steering  knuckle  pivot  pin  is  fastened.  A 
steering  arm  is  attached  to  the  wheel  core  and  moves 
the  wheel  to  the  angle  desired  for  steering. 

Automatic  Steering  Arrangement. — In  many  cases 
it  is  desirable  to  provide  means  so  that  a  tractor  and 
plough  outfit  can  be  operated  by  one  man  without 
difficulty.  This  may  be  done  in  two  ways.  Either 
the  steering  or  the  operation  of  the  machinery  the 
tractor  is  hauling  must  be  automatically  arranged. 
In  ploughing  with  the  lever  actuated  types  of  engine 
ploughs  the  engine  operator  can  attend  to  these  if  long 
furrows  are  being  ploughed  without  difficulty  if  an 
automatic  steering  arrangement  is  used.  A  typical 
construction  when  applied  to  a  tractor  having  a  centrally 
pivoted  one-piece  axle  is  shown  at  Fig.  136,  while  another 
form,  which  is  suitable  for  use  when  a  front  axle  of  the 
Ackerman  type  is  utilized,  is  depicted  at  Fig.  136-A. 
The  operation  of  these  devices  is  not  difficult  to  under- 
stand. As  usually  constructed  a  wheel  is  carried  by 
a  frame  extending  from  the  front  axle  which  drops 
into  the  last  furrow  cut.  If  the  furrow  is  moderately 
straight,  this  wheel  will  keep  the  tractor  axle  in  proper 
position  so  that  it  can  follow  any  slight  deviations 
from  a  true  course  made  in  cutting  the  last  furrow  with- 
out any  attention  from  the  operator. 

At  Fig.  136  it  will  be  apparent  that  when  a  front 
wheel  is  carried  at  the  extremity  or  apex  of  the  triangu- 
lar support  joining  it  to  the  axle,  which  forms  the  base, 


The  Modern  Gas  Tractor 


315 


310 


The  Modern  Gas  Tractor 


any  movement  of  the  wheel  will  be  transferred  back 
to  the  front  axle.  An  arrow  carried  at  the  end  of  a 
standard  so  that  it  can  be  conveniently  glanced  at 
by  the  operator  from  time  to  time  serves  as  a  direction 
indicator  and  a  guide  by  which  the  course  of  the  tractor 
or  any  deviation  from  a  correct  line  of  travel  will  be 


Fig.  136a. — The   Cuddy   Automatic    Steering    Device    Applied 
to  Aekerman  Type  Front  Axle. 

readily  ascertained.  In  the  device  shown  at  Fig.  136-A 
the  action  is  somewhat  similar  to  that  previously  de- 
scribed, except  that  two  wheels  are  used  and  a  system 
of    leverage    is    employed    to    change    the    direction    of 


The  Modern  Gas  Tractor 


317 


Fig.  137. — Showing  Important  Members  of  Conventional  Power 
Transmission  System. 


318  The  Modern  Gas  Tractor 

movement  of  the  main  steering  member  on  the  front 
axle. 

Methods  of  Final  Drive. — One  of  the  important 
problems  that  the  tractor  designer  is  called  upon  to 
solve  is  that  of  power  transmission  from  the  motor 
to  the  rear  wheels.  It  is  imperative  that  this  be  ac- 
complished with  as  little  loss  of  energy  as  possible 
because  the  power  loss  through  friction  of  gearing  is 
not  available  at  the  drawbar.  Unfortunately,  it  is 
necessary  to  employ  a  large  gear  reduction  between 
the  engine  and  the  tractor  rear  wheels  and  this  can 
only  be  accomplished  by  using  intermediate  gearing, 
which  is  interposed  between  the  bull  gears  on  the  wheels 
and  the  crankshaft  of  the  motor.  The  efficiency  of 
the  transmission  system  depends  largely  upon  the 
number  of  gears  used,  whether  these  are  smoothly  fin- 
ished or  merely  rough  cast  members  and  whether  they 
are  suitably  protected  from  the  abrading  action  of 
the  dirt  and  grit  present  in  field  work. 

Well  cut  steel  gearing,  properly  housed  in  a  dust-proof 
and  oil-tight  casing  can  be  kept  lubricated  and  there- 
fore maintained  to  a  high  degree  of  efficiency.  This 
is  more  easily  accomplished  with  countershaft  or  in- 
termediate gearing  than  with  the  main  bull  pinions  and 
gears.  It  is  necessary  in  most  constructions  that  these 
be  exposed  on  account  of  the  difficulty  which  obtains 
in  incasing  them  properly.  Several  tractors  are  built, 
however,  in  which  all  gearing  is  protected  from  grit 
and  kept  running  in  a  bath  of  lubricant  Obviously 
the  wear  will  be  less  on  gearing  of  this  nature. 

The  Conventional  Method. — The  conventional  ar- 
rangement of  driving  gearing  with  the  various  parts 
separated  in  order  that  their  construction  may  be  clearly 
ascertained  is  shown  at  Fig.    137.     The  power  of  the 


Tin:  Modern  Gas  Tractor 


319 


engine  is  first  directed  to  the  cross  shaft  shown  at 
A  This  is  mounted  on  ball  bearings  of  the  annular 
pattern  and  carries  at  one  extremity  a  large  spur  gear 
which  meshes  with  a  pinion  on  the  engine  crankshaft. 
A  sliding  member  composed  of  two  gears  is  adapted 
to  be  moved  back  and  forth  on  this  cross  shaft  by  a 


Fig.  138. — Front  View  of  Hackney  Gas  Tractor  Which  has 
Traction  Members  at  Front  End  and  Single  Rear  Wheel 
for  Steering. 

gear  shifting  collar  operated  through  a  hand  lever 
forming  part  of  the  control  system.  These  sliding 
gears  must  turn  with  the  cross  shaft  because  they  are 
kept  from  rotating   ndependently  of  it  by  a  substantial 


320  The  Modern  Gas  Tractor 

key  which,  however,  does  not  limit  their  lateral  motion. 
Immediately  back  of  this  cross  shaft  to  which  the  power 
from  the  engine  is  first  delivered,  another  countershaft 
assembly,  which  is  depicted  at  B,  is  mounted.  This 
is  spaced  in  such  a  way  that  the  sliding  gears  on  the 
main  shaft  of  the  transmission  may  be  moved  to  engage 
two  gears  bolted  to  the  differential  gear  casing.  When 
the  largest  gear  on  the  cross  shaft  is  in  mesh  with  the 
smallest  gear  on  the  differential  case  a  high  speed  is 
obtained  while  the  engagement  of  the  smaller  gear 
on  the  cross  shaft  with  the  larger  gear  attached  to  the 
differential  drum  gives  a  reduction  in  speed.  The  ar- 
rangement of  the  differential  gear  interior  is  just  the 
same  as  has  been  previously  described,  the  balancing 
mechanism  being  of  the  bevel  gear  and  pinion  type. 
As  is  true  of  all  differential  cross  shafts  the  right  and 
left  master  pinions,  which  engage  the  bull  gears  on  the 
rear  wheels,  are  driven  by  independent  shafts  from  the 
differential  gears.  The  rear  axle  is  of  the  usual  dead 
pattern  and  is  depicted  at  C.  Large  internal  spur 
gears  are  attached  to  the  wheel  rims  and  are  driven 
from  the  differential  cross  shaft  by  the  master  pinions. 
Use  of  Chains  and  Sprockets. — The  driving  method 
previously  considered  is  that  generally  followed  because 
with  the  large  driving  members  used  on  gas  tractors 
it  is  desirable  to  apply  the  power  as  near  to  the  rim 
as  possible.  In  some  form  of  tractors  the  drive  from 
the  differential  cross  shaft  to  the  traction  members 
is  by  chains  and  sprockets  such  as  are  used  widely  in 
automobile  engineering  practice.  This  permits  one  to 
locate  the  differential  gear  cross  shaft  at  any  convenient 
point  in  the  frame  as  the  drive  may  be  through  chains 
of  any  length  within  reasonable  limits.  The  view  at 
Fig.  138  is  that  of  the  front  end  of  the  Hackney  auto 


The  Modern  Gas  Tractor 


321 


Fig.  139.— Rear    View    of    Holt    Caterpillar    Tractor    Showing 
Chain  Drive  to  Traction  Members  From  Cross  Shaft. 

plough  which  is  unconventional  in  construction  inasmuch 
as  the  front  wheels  are  employed  as  traction  members 
while  a  single  rear  wheel  is  utilized  for  steering  purposes. 
This  method  of  drive  makes  it  possible  to  place  the 
engine  directly  over  the  wheels  as  shown  at  Fig.  13 
(Chapter  I)  and  carry  the  differential  cross  shaft  at  a 
point  about  mid-way  on  the  frame.  At  Fig.  139  the 
driving  chains  which  are  utilized  to  take  the  power  of 
the  engine   from   the   cross   shaft   mounted   above   the 


322  The  Modern  Gas  Tractor 

rear  axle  of  the  Holt  Caterpillar  Tractor  to  the  track- 
laying  sprockets  are  clearly  outlined. 

Live  Axle  Forms. — One  of  the  most  popular  types 
of  axles  used  in  automobile  practice  is  termed  "the 
full  floating"  live  axle.  In  this  construction  the  wheels 
are  driven  by  means  of  shafts  attached  to  them  by 
some  form  of  positive  clutch  while  they  themselves 
revolve  on  independent  bearings  carried  by  the  housings 
which  inclose  the  axle  shaft.  The  differential  gearing 
is  always  a  part  of  an  axle  of  this  pattern  and  is  mounted 
at  the  center  in  a  case  made  to  receive  it  and  the  shafts 
which  drive  the  wheels  are  attached  to  the  bevel  dif- 
ferential gears  in  just  the  same  manner  as  is  employed 
on  a  differential  cross  shaft.  This  method  of  axle  con- 
struction is  not  as  satisfactory  for  tractor  use  as  it  is  in 
its  automobile  applications,  first,  because  it  is  difficult 
to  obtain  the  desired  gear  reduction  by  the  single  pair 
of  gears  usually  employed  in  driving  the  differential  gear 
case,  and  second,  because  the  power  to  turn  the  wheel 
is  applied  at  its  center  instead  of  near  the  rim,  which 
places  severe  torsional  stresses  or  twisting  strains  on 
driving  shafts  when  used  in  connection  with  large 
diameter  wheels. 

A  number  of  tractor  manufacturers  are  experimenting 
with  this  form  of  axle  but  in  order  to  use  it  have  been 
forced  to  reduce  the  size  of  the  driving  members  which 
makes  this  form  of  construction  more  suitable  for 
combined  motor  trucks  and  tractors  than  for  the  regular 
pattern  traction  engines  used  generally  in  field  work. 
The  differential  drum  on  the  automobile  live  axle  is 
usually  driven  by  a  pair  of  bevel  gears,  the  desired 
reduction  ratio  of  23^  or  3  to  1  being  easily  obtained. 
In  order  to  provide  the  low  ratios  of  drive  needed 
between  the  engine  and  the  rear  wheels  of  gas  tractors 


The  Modern  Gas  Tractor 


323 


it  would  not  be  possible  to  employ  bevel  gears  carried 
directly  in  the  differential  housing.  The  use  of  worm 
gearing,  however,  enables  the  designer  to  employ  but 
a  single  pair  of  reduction  gears  in  the  rear  axle  though 
a  set  of  intermediate  gearing  is  necessary  to  provide 
a  partial  reduction  of  speed  before  the  power  is  directed 
to  the  worm  gear  of  the  axle. 

The  construction  of  a  worm  gear  driving  assembly 
is  clearly  shown  at  Fig.  140.    The  worm  gear  is  attached 


Single  Row 
\Batl  Bea ring 
\'\  :^XxN\  worm        PTT. 


New  Departure  Double  Row 
Ball  Bearing 


Fig.  140. — Sectional    View   of   Worm   Drive   Gearing   Used   in 
Connection  With  Live  Rear  Axle. 

to  the  differential  casing  and  is  revolved  by  means  of 
the  worm  mounted  above  it  and  connected  to  the 
speed  reducing  cross  shaft  back  of  the  engine.  In 
order  to  reduce  friction  to  a  minimum  the  worm  is 
mounted  on  New  Departure  ball  bearings  of  the  single 
and  double  row  types.  The  end  thrust  of  the  worm 
is  taken  by  a  large  double  row  bearing  which  is  clamped 
to  the  shaft  and  housing  in  such  a  manner  that  it  is 
restrained  from  lateral  movement  and  is  thus  able 
to  resist  thrust  in  either  direction  and  radially  applied 


324 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  325 

loads  as  well.  The  single  row  ball  bearing  of  the  con- 
ventional annular  pattern  has  a  floating  outer  race, 
i.  e.,  that  member  can  move  back  and  forth  to  some 
extent  should  the  worm  shaft  expand  clue  to  heating 
while  in  operation.  Gearing  of  this  character  is  carried 
in  an  oil-tight  container  and  as  the  differential  casing 
may  be  filled  with  lubricant  through  the  oil  filler  plug 
at  the  top  of  the  case  the  gearing  will  run  with  minimum 
depreciation  and  maximum  efficiency. 

The  view  at  Fig.  141  is  a  section  through  half  of  a 
worm  gear  driven  live  axle.  The  differential  assembly 
is  mounted  on  large  double  row  bearings  which  locate 
the  worm  gear  accurately  in  the  center  of  the  driving 
worm,  a  condition  necessary  to  secure  efficient  driving. 
The  rear  wheels  are  carried  by  two  double  row  ball 
bearings  the  inner  members  of  which  are  clamped  to 
and  supported  by  the  tube  or  housing  serving  to  inclose 
the  driving  alxe.  The  drive  shaft  turns  the  wheel  by 
means  of  a  positive  clutch  attached  to  the  end  of  the 
axle  shaft  and  fitting  into  suitable  depressions  in  the 
interior  periphery  of  the  wheel  hub.  An  advantage 
of  this  method  of  construction  is  that  the  differential 
gear  and  driving  axles  may  be  removed  if  necessary 
without  taking  off  the  wheels.  Owing  to  the  expense 
of  building  and  the  fact  that  this  method  of  axle  con- 
struction is  not  adapted  for  use  with  the  extremely  large 
diameter  driving  members  ordinarily  employed  on  gas 
tractors  it  is  obvious  that  the  systems  of  drive  in  which 
the  power  is  applied  to  the  rim  of  the  wheel  directly 
instead  of  through  the  medium  of  the  spokes  and  hub 
will  continue  to  be  most  popular  and  generally  satis- 
factory. 


CHAPTER  IX. 

DRIVING  AND  HOUSING  THE  TRACTION   ENGINE. 

How  to  Start  Traction  Engines — How  to  Start  Tractor — Typi- 
cal Tractor  Control  Systems — Advice  on  Tractor  Opera- 
tion— Housing  the  Tractor — Combined  Tractor  House  and 
Farm  Workshop — Fuel  Storage  Methods — Tools  and 
Equipment  for  Care  of  Tractor. 

How  to  Start  Traction  Engines. — As  a  rule 
before  shipment  from  the  factory,  all  of  the  reputable 
makes  of  gas  tractors  are  thoroughly  tested  with  and 
without  load  to  make  sure  that  all  parts  are  functioning 
properly.  This  includes  tests  of  the  motor  on  the 
block,  running  the  tractor  on  a  special  testing  track 
around  the  works  and  after  the  machine  has  been  in 
use  for  some  time,  determining  the  power  capacity  of 
the  motor  to  ascertain  if  it  approximates  the  standard 
established  by  means  of  a  brake  test  and  determining 
the  tractive  or  pulling  power  by  some  form  of  dyna- 
mometer test.  Therefore,  the  tractor  purchaser  receives 
a  machine  that  has  been  carefully  tested  and  that  should 
start  without  difficulty  if  the  proper  steps  are  taken. 

The  most  important  thing  to  do  before  endeavoring 
to  start  the  engine  is  to  see  that  the  fuel  and  water 
containers  are  full  and  that  all  the  electric  wiring  is 
properly  connected.  All  mechanical  oilers  should  be 
filled  with  the  proper  lubricant  and  if  a  constant  level 
splash  system  is  employed  enough  oil  to  insure  thorough 
lubrication  should  be  put   into   the   crank   case.     The 

326 


The  Modern  Gas  Tractor  327 

open  gears  should  be  well  covered  with  grease  and  all 
grease  cups  should  be  screwed  down  to  make  sure 
that  all  bearing  surfaces  fed  by  these  members  are 
receiving  the  proper  supply  of  lubricant.  Generally 
one  or  two  quarts  of  oil  will  be  sufficient  in  the  crank 
case  and  nothing  but  the  best  cylinder  oil  should  be 
used  for  this  purpose.  If  there  is  too  much  oil  in  the 
engine,  clouds  of  white  smoke  will  issue  from  the  exhaust 
pipe,  so  a  certain  amount  can  be  drained  from  the 
engine  case  by  means  of  petcock  or  drain  plug  provided 
for  the  purpose.  In  starting  a  new  engine  it  would  be 
well  to  remember  that  surplus  oil  will  do  no  harm  and 
that  plenty  of  oil  is  much  cheaper  than  repairs.  When 
the  engine  is  new  and  all  bearing  parts  are  still  stiff, 
copious  lubrication  is  one  of  the  surest  methods  of 
obtaining  a  smooth  running  machine. 

Before  attempting  to  start  the  engine  one  should 
become  familiar  with  the  various  control  levers  pro- 
vided both  for  controlling  the  speed  of  the  motor  and 
for  handling  the  various  clutches.  The  first  point  to 
make  sure  about  is  that  the  master  clutch  handle  is 
set  in  a  neutral  position,  i.  e.,  with  the  clutch  released. 
This  will  disconnect  the  engine  from  the  transmission 
and  will  permit  the  power  plant  to  run  independently 
of  the  rear  wheels.  The  spark  advance  lever  is  placed 
in  the  full  retarded  or  late  position,  the  lever  that  con- 
trols the  throttle  of  the  carburetor  is  set  so  this  member 
will  open  the  throttle  slightly  and  the  engine  may  be 
primed  by  pouring  a  little  gasoline  in  each  of  the  cylin- 
ders through  the  priming  cups  or  petcocks,  if  these 
are  provided.  The  switch  is  placed  on  the  side  of  the 
coil  marked  "battery"  if  a  double  ignition  system  is 
provided.  The  engine  is  turned  over,  either  by  means 
of  a  starting  handle  attached  to  the  crankshaft  or  by 


328 


The  Modern  Gas  Tractor 


rocking  the   flywheel   on  those   types  of   tractors  that 
are  not  provided  with  a  starting  crank. 

After  the  engine  crankshaft  has  been  turned  over 
two  or  three  times  a  sharp  hiss  will  be  heard  at  one 
of  the  priming  cocks  accompanied  by  a  sheet  of  flame. 
The  priming  cocks  are  then  closed  and  the  engine  crank- 
shaft is  given  a  brisk  turn  until  one  of  the  pistons  passes 


Fig.  142. — Side   View   of   Morris   Tractor   Showing   Operator's 
Platform  and  Control  Levers. 

its  compression  and  ignition  point.  The  engine  should 
start  off  at  once  if  everything  is  right.  After  the  power 
plant  has  started  and  is  running  at  the  proper  speed, 
throw  the  switch  lever  to  the  side  of  the  switch  marked 
"magneto"  but  keep  the  throttle  of  the  carburetor 
nearly   closed   until   ready  to  start  the  tractor.     This 


The  Modern  Gas  Tractor 


329 


will  prevent  the  engine  from  racing  and  the  crankshaft 
will  turn  at  a  comparatively  low  speed.  By  referring 
to  the  view  of  the  tractor  shown  at  Fig.  142,  the  loca- 
tion of  the  operator's  platform  and  control  levers  are 
easily  determined.  In  this  machine,  it  is  necessary 
to  start  the  engine  by  rocking  the  large  flywheel  or  turn- 
ing it  over  until  the  pistons  have  drawn  in  a  charge  of 
gas  and  it  has  been  compressed  ready  for  ignition. 


Fig.  143. — Governors  of  the  Centrifugal  Type  Form  Important 
Part    of    Tractor    Power    Plant    Control    Svstem. 


While  most  tractor  power  plants  are  provided  with 
automatic  centrifugal  governors,  such  as  shown  at 
Fig.  143,  to  keep  the  engine  from  racing  even  if  the 
throttle  lever  is  open,  they  are  set  so  that  the  engine 
speed  will  be  higher  than  is  desirable  when  running 
light.      These   governors   are   made   in   two   forms,    the 


?,:>()  The  Modern  Gas  Tractor 

type  generally  used  being  shown  in  illustration.  The 
tractor  power  plant  may  be  controlled  by  a  throttling 
governor  or  by  a  hit  and  miss  system  which  is  employed 
when  engines  of  the  stationary  type  are  utilized  as 
power  plants.  The  centrifugal  governor  is  the  most 
popular  where  the  engine  is  supplied  with  gas  by  a 
carburetor  provided  with  a  throttle  so  that  the  amount 
of  vapor  supplied  the  cylinders  may  be  regulated.  The 
principle  of  the  centrifuga  governor  is  easily  under- 
stood When  the  speed  of  the  engine  increases  to  a 
point  where  it  is  desirable  to  reduce  it  the  weights 
attached  to  the  governor  arms  fly  out  on  account  of 
centrifugal  force  and  close  the  throttle,  this  slowing 
up  the  engine. 

The  governor  shown  at  A  (Fig.  143)  forms  part  of 
the  mixing  or  vaporizing  valve  that  supplies  mixture 
to  the  cylinders.  It  is  driven  by  means  of  a  small, 
flat  belt  running  from  the  engine  crankshaft  to  a  pulley 
on  the  governor.  The  power  from  the  horizontal  shaft 
is  transmitted  to  the  vertical  revolving  member  that 
carries  the  governor  weight  and  spring  assembly  by  a 
pair  of  small  miter  gears.  The  governor  shown  at  B 
is  similar  in  construction,  except  that  it  is  provided 
with  a  case,  the  cover  of  which  is  removed  to  outline 
construction  of  interior  mechanism.  The  tendency  of 
the  weights  to  fly  out  is  changed  to  a  reciprocating 
motion  of  small  plunger  rod  members  which  oscillate 
the  shaft  carried  at  the  base  of  the  casing  to  which  the 
throttle  lever  is  attached.  This  form  of  governor  is 
driven  directly  by  means  of  a  bevel  gearing  carried 
inside  of  the  engine  base.  In  some  tractors  the  control 
system  is  so  arranged  that  the  governor  may  be  cut 
out  at  will  and  the  power  plant  controlled  solely  by 
the  throttle  lever,  if  it  is  desired  to  augment  the  speed 


The  Modern  Gas  Tractor 


331 


of  the  engine  beyond  that  point  to  which  the  governor 
is  set. 

As  a  rule  it  is  not  difficult  to  start  a  multiple  cylinder 
engine  by  the  hand  starting  crank  provided,  or  by  rocking 
the  flywheel.  In  some  cases  where  a  one  or  two  cylinder 
engine  of  large  capacity  is  utilized  it  is  difficult  to  start 
these  by  hand  unless  conditions  are  exceptionally  favor- 
able.    The  difficulty  usually  encountered  in  setting  in 


Fig.  144. — Small  Engine  Used  to  Start  Large  Power  Plant  of 
I.  H.  C.  "Mogul"  Tractor. 

motion  a  large  engine,  especially  in  cold  weather,  when 
the  oil  in  the  cylinder  has  congealed,  is  ingeniously 
overcome  on  the  I.  H.  C.  45  horse-power  Mogul  tractor 
by  providing  a  1  horse-power  engine  of  the  air  cooled 
type  to  turn  the  crankshaft  of  the  power  plant  over. 
This  little  engine,  which  is  illustrated  at  Fig.  144,  relieves 
the  operator  of  all   labor  of  revolving  the  heavy  fly- 


332  The  Modern  Gas  Tractor 

wheel  by  hand  against  partial  compression  that  is  neces- 
sary on  some  large  tractors. 

This  starting  engine  is  a  complete  little  power  plant 
in  itself  and  is  equipped  with  its  own  gasoline  tank 
and  battery  box.  It  is  an  air  cooled  motor  of  the  four- 
cycle type  with  an  inclosed  crankcase.  A  jump  spark 
ignition  system  composed  of  batteries  and  induction 
coil  is  provided  while  the  gasoline  tank  holds  one  gallon 
and  is  mounted  on  brackets  extending  from  the  cylinder 
casting.  A  small  friction  wheel  43^  inches  in  diameter 
with  a  5-inch  face  is  keyed  to  the  crankshaft  extension. 
The  engine  crankcase  is  hinged  on  a  shaft  carried  by  a 
base  casting  while  the  cylinder  is  steadied  by  a  rod 
attached  to  the  engine  base  by  an  eccentric  bearing. 
This  can  be  operated  by  a  hand  lever  so  the  cylinder 
may  be  tilted  a  short  distance  and  the  friction  pulley 
brought  to  bear  against  the  tractor  engine  flywheel 
outer  periphery.  The  engine  is  clamped  to  the  tractor 
frame  with  four  quickly  detachable  fasteners  and  may 
be  easily  removed  and  used  for  other  work  around  the 
farm  if  the  tractor  is  not  in  use. 

When  starting  the  larger  engine,  the  first  step  is 
to  throw  in  the  compression  relief  cam  of  the  main  power 
plant  so  that  the  piston  will  be  resisted  by  only  partial 
compression.  The  small  starting  engine  is  put  into 
operation  and  allowed  to  run  free  for  a  minute  or  two 
till  it  attains  sufficient  speed  to  develop  full  power. 
When  this  has  been  done,  the  lever  rotating  the  eccentric 
bearing  on  the  starting  engine  is  pulled  up  till  the 
friction  pulley  is  pressed  against  the  large  engine  fly- 
wheel. Owing  to  the  difference  in  diameter  between 
the  flywheel  and  the  small  friction  pulley  the  starting 
engine  rotates  the  large  crankshaft  at  sufficient  speed 
for  starting  even  if  the  large  engine  does  not  operate 


The  Modern  <1as  Tractor 


:VM>> 


Fig.  145. — Rear  View  of   I.   H.   C.   Tractor   Showing   Control 
Levers  and  Operator's  Platform. 

easily.  When  the  large  engine  starts,  the  compression 
relief  cam  is  thrown  out  so  that  the  piston  gets  the 
benefit  of  full  compression  and  the  small  starting  engine 
is  tilted  back  and  stopped. 

How  to  Start  Tractor. — After  the  engine  has  been 
started  and  has  run  long  enough  so  that  it  is  thoroughly 
warmed  up  and  operating  efficiently  the  next  step  is 
to  start  the  traction  engine  itself.  The  type  of  trans- 
mission employed  will  determine  the  number  of  levers 
used   to   control   the   various   speeds   and   forward   and 


334  The  Modern  Gas  Tractor 

reverse  motion.  A  one  speed  tractor  will  be  much 
simpler  to  operate  than  a  form  having  a  two  or  three 
speed  gear  box.  The  control  platform  of  a  one  speed 
tractor  is  shown  at  Fig.  145.  It  will  be  seen  that  there 
are  two  hand  levers,  a  foot  pedal  and  a  hand  wheel 
used  to  control  the  machine.  One  of  the  hand  levers 
is  used  as  a  reverse  member,  while  the  other  controls 
the  master  clutch.  The  hand  wheel  is  utilized  to  move 
the  front  axle  for  steering  purposes  and  the  pedal  applies 
the  brake  when  it  is  desired  to  stop. 

If  the  tractor  is  to  be  run  in  a  forward  direction  the 
reverse  lever  is  set  in  the  notch  corresponding  to  the 
"go  ahead"  position.  The  master  clutch  has  been  dis- 
connected before  the  engine  started  and  for  this  reason 
the  reverse  lever  can  be  moved  as  desired  without  pro- 
ducing any  movement  of  the  tractor.  The  point  should 
be  emphasized  that  in  no  case  should  a  reverse  lever 
be  moved  without  the  master  clutch  being  disengaged. 
When  ready  for  the  load,  the  throttle  is  opened  and  the 
spark  lever  is  advanced,  this  allowing  the  engine  to 
run  at  a  speed  where  it  will  develop  its  power.  The 
master  clutch  lever  is  then  pushed  forward  or  pulled 
back  (depending  upon  the  design)  so  the  clutch  is  engaged 
very  slowly  and  gradually.  When  the  tractor  has  at- 
tained a  certain  amount  of  momentum,  the  clutch  control 
lever  may  be  pushed  to  its  extreme  "on"  position  after 
which  it  needs  no  further  attention  until  it  is  desired 
to  stop  the  tractor.  The  operator  need  only  be  con- 
cerned with  directing  the  machine  by  means  of  the 
steering  gear.  If  the  machine  is  running  too  fast  the 
engine  speed  may  be  reduced  by  closing  the  throttle, 
whereas  if  it  is  not  running  fast  enough  its  speed  may 
be  augmented  by  opening  the  throttle  and  supplying 
more  gas  to  the  engine. 


The  Modern  Gas  Tractor 


VSo 


To  stop  a  tractor  the  first  step  is  to  close  the  throttle, 
throw  out  the  clutch,  retard  the  spark  lever  and  apply 
the  foot  brake.  If  the  stop  is  to  be  a  lengthy  one,  the 
engine  may  be  put  out  of  operation  by  throwing  off 
the  ignition  switch  and  closing  the  gasoline  valve  at 
the  tank.  The  clutch  lever  should  always  be  kept 
in  the  "off'   position  unless  the  reverse  lever  is  provided 


Fig.  146. — Control  Levers  and  Starting  Crank  of  "Twin  City 
40"  Gas  Tractor. 

with  a  "neutral"  notch,  in  which  position  it  is  not  con- 
nected to  either  forward  or  reverse  drive  gears  and 
then  the  master  clutch  may  be  let  in  if  desired.  It  is 
not  desirable  to  leave  the  clutch  in  if  the  tractor  is  to 


::.".('»  The  Modern  Gas  Tractor 

make  a  stop  of  any  moment  because  considerable  strain 
may  be  present  in  the  parts  of  the  clutch  actuating 
mechanism  which  had  better  be  released. 

Typical  Tractor  Control  Systems. — In  order  to 
enable  the  reader  to  understand  the  functions  of  the 
various  control  levers  thoroughly  a  number  of  control 
systems  of  typical  tractors  are  outlined  at  Figs.  146, 
147  and  148.  That  at  Fig.  146  forms  part  of  the  "Twin 
City  40"  gas  tractor.  The  lever  A  is  used  to  set  the 
gearing  in  either  forward  or  reverse  motion  and  when 
in  the  position  shown  is  at  a  neutral  point  or  between 
the  two  positions.  The  lever  B  is  utilized  to  throw 
in  and  release  the  master  clutch.  The  switch  handle 
C  is  carried  on  the  face  of  the  induction  coil  and  may 
be  moved  to  the  right  or  left  to  couple  either  battery 
or  magneto  to  the  ignition  system.  The  throttle  lever 
D  is  in  the  full  open  position  when  pulled  back  to  the 
extreme  limit  of  the  quadrant.  The  spark  lever  E  is 
in  full  retard  position  when  thrown  to  the  other  ex- 
tremity of  the  quadrant,  as  indicated.  A  starting 
crank  F  is  utilized  to  turn  over  the  crankshaft  of  the 
motor.  Steering  is  by  hand  wheel  of  the  conventional 
pattern.  The  instructions  given  by  the  makers  for 
operating  this  tractor  follow: 

To  Start  Motor:  1. — Fill  priming  cups  on  top  of 
motor  with  gasoline.  Open  petcocks  and  allow  the 
gasoline  to  flow  into  the  cylinders.  If  motor  is  very 
cold  two  or  three  injections  of  fuel  may  be  required, 
while  if  motor  is  very  warm,  very  little  gasoline  and 
often  no  priming  is  necessary. 

2. — Close  priming  cocks  and  open  relief  cocks  on  side 
of  motor. 

3. — Referring  to  Fig.  146,  use  the  following  directions 
for  starting  motor  and  engaging  traction:      Place  lever  A 


The  Modern  Gas  Tractor  337 

in  the  central  notch  of  the  quadrant,  throw  in  the  clutch 
with  lever  B  which  is  done  by  pushing  it  forward.  Re- 
tard the  ignition  spark  by  throwing  lever  E  forward 
as  shown  in  the  illustration.  Open  the  throttle  by 
moving  lever  D  backward,  as  indicated.  Throw  the 
switch  lever  C  in  contact  with  point  marked  "B"  for 
batteries.  Turn  over  engine  crankshaft  with  starting 
handle  F.  As  soon  as  the  motor  starts  close  the  relief 
cocks,  throw  out  the  clutch  with  lever  B  and  stop  the 
clutch  shaft  by  bearing  down  on  the  brake  pedal  Q. 
Throw  the  switch  lever  C  onto  side  of  switch  marked 
"M"  which  is  the  magneto  side  and  advance  the  spark 
with  lever  E  by  pulling  it  backward. 

To  Engage  Traction:  For  traveling  forward  move 
the  lever  A  into  rear  notch  of  the  quadrant;  for  reverse 
motion  push  it  forward  into  the  other  notch.  Never 
move  lever  A  when  clutch  is  running  at  high  speed. 
If  this  lever  cannot  be  moved  from  neutral  to  either 
side  readily,  revolve  the  clutch  shaft  very  slowly  by 
barely  engaging  ever  B  and  keep  one  foot  on  brake 
pedal  Q  to  prevent  rapid  movement  of  clutch.  Always 
engage  lever  B  gradually,  as  engaging  the  master  clutch 
too  quickly  will  stall  the  motor  or  impose  severe  strains 
in  the  driving  gears.  A  gas  tractor  is  a  heavy  mass 
of  metal  and  should  be  put  in  motion  very  slowly, 
the  clutch  being  allowed  to  slip  until  sufficient  momentum 
has  been  attained  so  that  clutch  may  be  fully  engaged 
without  shock.  Control  speed  by  spark  and  throttle 
levers. 

The  control  system  outlined  at  Fig.  147  is  utilized 
on  the  Holt  Caterpillar  tractor  and  the  same  instruc- 
tions for  starting  the  engine  previously  given  will  apply 
in  this  case  as  well.  The  engine  speed  is  regulated  by 
the  usual  form  of  spark  and  throttle  levers  mounted 


838 


The  Modern  Gas  Tractor 


on  a  quadrant,  just  forward  of  the  steering  wheel. 
Four  clutch  levers  are  provided.  The  one  nearest  the 
steering  wheel  is  used  to  throw  the  master  clutch  in 
the  engine  flywheel  on  or  off  as  desired.  A  reverse 
lever  which  can  be  set  at  either  neutral  position  as 
indicated  or  for  forward  or  reverse  motion  is  provided 


Fig.  147. — Control  System  of  Holt  Caterpillar  Tractor  Showing 
Important  Elements. 

convenient  to  the  operator  and  back  of  the  master  clutch 
lever.  The  other  two  hand  levers,  which  are  placed 
alongside  of  the  master  clutch  control  lever,  are  utilized 


The  Modern  Gas  Tractor 


339 


Speed  change  operating  lever. 
Also  disengages  the  traction 

Timer  and  throttle 


Clutch  operating  leuer.    One  only  for 
threshing  and  field  work. 


/Steering  wheel. 


-Operator's  seat. 
-Reverse  lever. 


Draw  bar,  showing 
adjustable  hook-up 
clamps. 


Fig.  148. — Operator's     Cab     of     Pioneer     Gas     Tractor     Wit  It 
Important  Parts  of  Control  System  Indicated. 

to  operate  clutches  necessary  for  steering  with  a  Cater- 
pillar Tread. 

Steering  the  tractor  is  accomplished  by  releasing  the 
friction  clutch  which  drives  the  caterpillar  traction 
member  that  is  on  the  inside  of  the  circle  when  making 


340  The  Modern  Gas  Tractor 

a  turn,  in  connection  with  the  usual  form  of  hand 
wheel.  With  this  form  of  traction  member,  steering 
by  the  front  wheel  accomplishes  but  little  unless  the 
steering  clutch  is  disengaged  to  correspond  with  the 
direction  one  wishes  to  turn.  After  disengaging  the 
inside  friction  lever  the  degree  of  turning  depends  on 
the  angle  of  the  front  wheel.  The  mode  of  procedure 
in  steering  around  a  corner  is  as  follows:  When  about 
to  make  a  turn,  disengage  the  clutch  lever  that  controls 
the  friction  clutch  driving  the  traction  member  that 
is  to  be  on  the  inside  of  the  circle  first,  then  turn  the 
front  wheel  and  as  the  curve  is  made  straighten  the 
front  wheel  and  engage  the  friction  clutch  that  has 
been  released  when  the  tractor  is  again  headed  in  a 
straight  line  The  control  of  this  form  of  tractor  is 
not  radically  different  from  the  wheel  form  except 
that  care  must  be  taken  to  always  release  one  of  the 
steering  clutches  to  provide  a  certain  differential  action 
as  no  differential  gear  is  fitted. 

The  control  group,  which  is  inside  of  the  operator's 
cab  of  the  Pioneer  gas  tractor,  is  outlined  at  Fig.  148. 
In  this,  the  motor  speed  is  regulated  by  the  usual  spark 
and  throttle  levers  mounted  on  a  quadrant  forward 
of  the  steering  wheel.  Three  hand  levers  are  provided. 
One  is  the  reverse  lever,  operating  on  a  notched  segment, 
so  that  it  may  be  set  either  in  neutral,  forward  or  reverse 
positions.  The  other  large  lever  provided  with  a  latch 
is  a  clutch  operating  lever  while  the  changes  of  speed 
are  obtained  by  moving  a  third  hand  lever  which  shifts 
the  sliding  gears  of  the  gearset.  Steering  is  by  the 
conventional  form  of  hand  wheel.  This  tractor  is  dis- 
tinctive in  that  the  cab  is  entirely  inclosed  to  protect 
the  operator  from  the  elements  and  that  a  comfortable 
upholstered    seat    is    provided    for    him.      The    general 


The  Modern  Gas  Tractor  341 

rules  that  have  been  given  for  the  control  of  other  tractors 
apply  just  as  well  to  this  machine. 

Advice  on  Tractor  Operation. — The  operation  of 
a  gas  tractor  will  not  prove  difficult  to  an  engineer 
familiar  with  steam  tractor  operation  or  to  one  who 
is  familiar  with  automobile  driving.  The  main  point 
to  remember  is  that  the  tractor  may  be  stopped  im- 
mediately by  disengaging  the  master  clutch  and  applying 
the  brakes.  One  who  has  never  controlled  a  heavy 
machine  of  this  character  will  first  have  to  become 
familiar  with  operation  of  the  steering  mechanism.  An 
automobile  is  provided  with  a  steering  gear  that  is  quick 
to  act  and  one  and  a  half  turns  of  the  steering  wheelis 
all  that  is  necessary  to  turn  the  wheels  from  one  extreme 
position  to  the  other.  This  sensitiveness  is  necessary 
on  account  of  the  high  speed  automobiles  are  capable 
of.  With  a  tractor  conditions  are  different,  the  speed 
is  low  and  considerable  weight  is  supported  by  the 
front  wheels.  This  means  that  a  greater  number  of 
turns  of  the  hand  wheel  will  be  required  to  steer  a  tractor 
than  will  be  needed  to  direct  a  motor  car.  This  is 
necessary  because  less  effort  is  required  from  the  operator 
on  account  of  the  lower  ratio  on  the  worm  reduction 
gearing,  and  as  the  tractor  is  traveling  at  a  compara- 
tively low  speed  the  operator  has  ample  time  to  turn 
the  hand  wheel  any  number  of  times  that  may  be  desired 
to  insure  movement  of  the  front  wheels.  Most  tractors 
are  provided  with  a  crank  or  small  handle  extending 
from  the  rim  of  the  steering  wheel  so  that  this  member 
may  be  revolved  at  a  higher  rate  of  speed  than  would 
be  possible  if  it  were  grasped  around  the  rim. 

The  tractor  operator  should  always  be  careful  when 
operating  on  highways  to  avoid  hollows  or  soft  ground 
and  mudholes  should  always  be  passed  by  making  a 


342  The  Modern  Gas  Tractor 

detour  instead  of  steering  the  heavy  machine  recklessly- 
through  them.  Care  should  be  taken  in  passing  over 
bridges  to  make  sure  that  these  are  of  ample  strength 
as  many  flimsily  built  wooden  structures  have  failed 
under  the  great  weight  of  the  tractor  for  which  they 
were  never  designed.  If  the  tractor  becomes  mired  and 
the  differential  lock  is  not  available  pieces  of  plank, 
brush,  straw  or  anything  that  will  help  traction  may 
be  put  under  the  driving  wheels.  If  one  wheel  is  on 
dry  land  a  tractor  will  often  free  itself  provided  that 
the  differential  gear  is  temporarily  put  out  of  commis- 
sion. This  can  easily  be  done  on  most  tractors  by  bolt- 
ing a  lever  carried  by  the  revolving  axle  shaft  to  the 
wheel  hub  that  normally  revolves  free  around  it  when 
the  differential  gear  is  in  operation.  This  insures  that 
both  wheels  will  turn  with  the  axle  and  the  wheel  that 
is  on  dry  land  will  provide  traction  enough  to  move 
the  machine  under  these  conditions.  If  the  differential 
gear  were  in  operation  the  traction  member  that  was 
in  the  mudhole  and  which  had  the  least  adhesion  with 
the  ground  would  just  spin  around,  whereas  the  other 
member  would  remain  stationary. 

On  two  and  three  speed  tractors  the  operator  should 
always  use  that  ratio  best  suited  for  the  work  the 
tractor  is  doing.  In  getting  from  place  to  place  over 
the  roads  and  for  hauling  light  loads  the  highest  speed 
of  a  three  speed  tractor,  which  is  about  six  miles  an 
hour,  can  be  used.  For  hauling  heavier  loads  over  the 
highways  the  medium  speed,  which  is  about  three  and 
one-half  or  four  miles  per  hour,  will  give  the  best  results. 
For  drawbar  work  where  considerable  power  is  needed 
the  lowest  gear  ratio,  which  is  seldom  over  two  miles 
per  hour,  should  be  used  The  tractor  should  not  be 
operated  on  the  low  gear  except  when  conditions  demand 


The  Modern  Gas  Tractor  348 

it  and  if  the  load  is  light  it  is  preferable  to  run  on  one 
of  the  higher  gears  and  throttle  the  engine  down  than 
it  is  to  run  on  a  low  gear  ratio  and  run  the  engine  at 
full  speed. 

When  operating  a  tractor  over  hard  roads,  especially 
those  of  the  macadamized  variety,  the  operator  owes 
it  to  the  public  to  remove  the  grouters,  traction  points 
or  mud  lugs  from  the  rear  wheels  and  run  on  the  smooth 
steel  tire.  The  use  of  grouters  cuts  up  a  road  too  much, 
whereas  running  with  steel  tires  will  offer  enough  ad- 
hesion to  secure  traction  on  a  hard  road  and  at  the  same 
time  the  road  is  benefited  by  the  rolling  action  of  the 
large  wheels,  rather  than  being  cut  up  as  is  the  case 
when  the  projections  ordinarily  fitted  to  increase  trac- 
tion in  the  field  are  fitted. 

Housing  the  Tractor. — The  average  farmer  is  apt 
to  be  negligent  in  providing  suitable  quarters  in  which 
the  various  farm  machines  may  be  stored.  It  is  a  com- 
mon sight  to  travelers  on  trains  leaving  the  East  for 
the  Middle  West  to  find  costly  agricultural  machinery 
out  in  the  open  fields  alongside  of  the  tracks.  If  this 
was  confined  to  but  one  section  of  the  country  it  would 
be  reasonable  to  assume  that  the  failing  was  not  a 
common  one,  but  the  observant  traveler,  especially  if  he 
has  economical  instincts  and  is  familiar  with  machinery, 
will  note  practically  the  same  condition  existing  in  all 
States  through  which  he  passes.  In  one  field  a  mowing 
machine  will  be  seen  half  mired  in  a  swamp  with  its 
vital  parts  rusting  away.  In  another  case  it  may  be 
only  a  plough  or  hay  rake  or  a  toothed  harrow,  but 
nevertheless,  these  less  expensive  machines  are  wholly 
without  protection  and  are  covered  with  rust.  This 
sort  of  treatment  means  that  machines  which  should 
have  a  normal  working  life  of  from  five  to  ten  years, 


344  The  Modern  Gas  Tractor 

depreciate  so  rapidly  that  a  perpetual  mortgage  must 
be  kept  on  the  farm  in  an  endeavor  to  supply  the  new 
machines  which  are  needed  very  often. 

Exposure  to  the  elements  is  not  good  for  any  form  of 
machinery  composed  of  wood  and  metal.  The  wood 
will  rot  while  the  metal  portions  oxidize  away  and  all 
bearing  points  and  moving  parts  become  so  clogged 
with  rust  that  when  the  machine  is  put  in  service  again 
considerable  time  is  needed  to  place  in  a  condition  where 
it  will  be  able  to  do  any  kind  of  work.  In  several  cases 
the  writer  has  observed  traction  engines  hauled  up 
alongside  of  some  decrepit  shed  or  out-house  and  covered 
with  a  tattered  old  piece  of  canvas  or  banked  half  way 
up  in  a  snow  drift.  Of  course,  it  is  generally  known  that 
the  running  gear  portions  of  a  traction  engine  are  not 
very  sensitive  but  this  does  not  mean  that  a  tractor 
should  not  be  given  that  protection  from  the  elements 
that  is  so  necessary  to  secure  maximum  service  and 
minimum   depreciation. 

Even  the  cheapest  tractors  represent  an  investment 
of  $1,000  or  more  and  it  is  not  reasonable  of  the  farmer 
to  expect  good  service  from  a  machine  which  he  leaves 
exposed  to  all  conditions  of  wind  and  weather.  An 
old  awning  or  tent  cover  or  a  lot  of  old  bagging  is  not 
sufficient  protection  for  a  piece  of  machinery  that  is 
as  costly  as  a  tractor.  Even  the  poorest  farmer  will 
take  the  proper  steps  to  protect  his  live  stock  and  in 
many  cases  these  are  housed  in  more  pretentious  quarters 
than  he  and  his  family  share.  It  is  not  necessary  that 
the  tractor  house  should  be  an  expensively  constructed 
or  ornate  structure  but  it  is  imperative  that  it  be  sub- 
stantial and  weather  proof.  Very  satisfactory  houses 
may  be  erected  for  a  few  hundred  dollars  that  will 
insure  adequate  protection  to  the  tractor. 


The  Modern  Gas  Tractor 


345 


~*l 


o 

If 


o 


sai/c/dng 


S-H- 


34(5  The  Modern  Gas  Tractor 

The  farmer  about  to  build  a  house  for  his  tractor  must 
choose  between  several  different  types  of  construction 
and  in  addition  to  local  conditions  he  must  be  governed 
in  this  selection  by  proper  consideration  of  cost,  safety, 
durability  and  fire  protection.  The  tractor  house  may 
be  of  simple  frame  construction,  consisting  of  ordinary 
odds  and  ends  of  lumber  and  old  planks  from  some 
demolished  barn  or  shed  as  the  cheapest  example  to 
the  more  expensive  but  substantial  houses  made  of 
new  lumber.  The  shed  may  be  an  all  steel  structure  with 
studding  composed  of  various  light  structural  iron  shapes, 
such  as  angles,  tees,  or  channels  covered  with  corrugated 
sheet  iron.  Of  late  there  is  considerable  attention  being 
paid  to  concrete  construction  and  if  the  farmer  has  a 
gravel  bank  on  his  land  this  will  make  the  most  satis- 
factory form  of  building. 

In  considering  the  cheaper  types  of  frame  construc- 
tion for  tractor  houses,  these  may  be  neglected  as  un- 
suitable for  permanent  installation  because  of  lack  of 
durability  and  an  undesirable  fire  risk  which  should 
be  given  careful  consideration  if  one  intends  to  use  the 
power  plant  of  the  tractor  as  stationary  engine  during 
the  time  that  the  tractor  is  not  in  use  in  the  field.  A 
steel  construction,  while  very  efficient  and  satisfactory, 
is  usually  so  great  in  first  cost  that  this  will  generally 
prohibit  its  use  for  the  ordinary  tractor  house.  Rein- 
forced concrete,  through  the  reduction  in  price  of  first- 
class  Portland  cement  and  the  development  of  very 
satisfactory  and  economical  mixtures,  has  been  receiving 
considerable  attention  because  a  very  substantial  build- 
ing may  be  erected  at  low  cost  and  in  a  comparatively 
short  space  of  time. 

A  building  of  this  nature  is  free  from  vibration,  does 
not  require  repairs  or  renewal,  and  offers  the  maximum 


The  Modern  Gas  Tractor 


348  The  Modern  (J as  Tractor 

fire  protection.  The  exact  cost  of  a  building  in  any 
case  is  governed  by  local  conditions.  In  considering 
wood  construction  one  should  remember  that  skilled 
laborers  are  required  to  do  a  really  satisfactory  job, 
though  very  substantial  stiuctures  have  been  erected 
by  the  farmer  and  his  help  without  the  assistance  of 
a  highly  paid  carpenter.  In  making  a  building  of  con- 
crete one  must  consider  the  price  of  cement,  the  cost 
of  obtaining  suitable  sand,  broken  stone  or  gravel,  the 
price  of  lumber  for  forms  and  the  wages  of  laborers. 
As  concrete  is  largely  laid  by  the  cheapest  kind  of  labor 
the  high  rates  necessary  to  pay  for  the  skilled  laborers 
needed  with  wood  or  steel  construction  can  be  eliminated. 

In  designing  the  tractor  house,  assuming  that  one 
has  to  be  built  specially  for  it,  one  should  make  provision 
to  build  a  structure  enough  larger  than  absolutely  needed 
to  shelter  the  tractor  so  a  small  work  bench  may  be 
provided  and  also  ample  storage  space  for  the  various 
supplies  and  spare  parts  needed  to  insure  continual 
operation  of  any  piece  of  machinery.  If  buildings  are 
already  available  one  should  be  careful  to  select  a  struc- 
ture which  has  no  cellar  because  the  average  floor  of  a 
barn  or  stable  is  not  strong  enough  to  support  the 
great  weight  of  a  traction  engine  which  ranges  from  four 
tons  for  a  12  horse-power  type  to  fifteen  tons  for  the 
45  and  60  horse-power  forms.  Care  should  always  be 
taken  when  a  building  with  a  basement  is  used  that 
the  floor  is  well  shored  up  by  additional  posts  and 
strengthened  by  additional  heavy  planking  to  bear  the 
excess  strain  for  which  it  was  not  originally  calculated. 

The  size  of  the  building  depends  largely  upon  the 
size  of  the  tractor  that  is  to  be  housed.  A  traction 
engine  will  vary  in  width  from  7  feet  6  inches  to  10 
feet,  and  as  it  is  desirable  to  have  space  on  all  sides, 


The  Modern  <Jas  Tractor  :!4!» 

it  will  be  well  to  make  the  shed  in  which  the  tractor 
is  to  be  housed  at  least  18  or  20  feet  in  width.  The 
extreme  length  of  a  tractor  will  vary  from  15  feet  to 
20  feet  and  here  again  we  should  provide  plenty  of 
room  so  that  a  building  30  feet  long  will  give  ample 
space  for  housing  the  largest  tractor.  The  average 
tractor  will  be  about  10  feet  high,  therefore  the  build- 
ings provided  for  its  use  should  have  doors  11  feet  in 
height  and  about  12  feet  in  width. 

Combined  Tractor  House  and  Farm  Workshop. — 
There  is  another  point  in  which  the  average  farmer 
is  somewhat  lax  and  that  is  providing  himself  with  a 
shop  of  adequate  size  and  with  suitable  equipment  to 
make  ordinary  repairs  on  the  various  farm  appliances. 
The  farm  that  is  up-to-date  enough  to  own  a  gas  tractor 
should  be  sufficiently  progressive  to  provide  a  well- 
equipped  shop  where  not  only  the  tractor  can  be  repaired 
but  the  other  farm  tools  receive  attention  when  needed. 
A  very  satisfactory  method  of  doing  this  is  to  make  a 
combined  tractor  house  and  farm  workshop,  as  outlined 
at  Fig.  149.  While  one  is  putting  up  the  garage  for 
the  tractor,  it  does  not  prove  much  more  expensive  to 
enlarge  the  structure  somewhat  and  have  a  separate 
room  in  which  the  various  tools  needed  to  do  wood 
work  and  metal  work,  such  as  smithing,  can  be  housed. 
It  is  not  expected  of  the  average  farmer  that  he  qualifies 
as  a  blacksmith  or  machinist,  but  at  the  same  time 
there  are  many  little  tasks  that  he  can  do  just  as  well 
as  the  blacksmith  or  wagon  builder  that  will  not  only 
save  money  by  providing  work  for  a  period  of  leisure 
when  conditions  do  not  permit  outside  work  to  be 
carried  on  but  that  may  also  save  valuable  time  during 
the  rush  period  of  ploughing,  seeding,  or  harvesting 
by  saving  a  trip  to  town. 


350 


The  Modern  Gas  Tractor 


A  shop  may  be  equipped  with  all  necessary  wood  and 
metal  working  tools  to  make  ordinary  repairs  for  con- 
siderably less  than  S100.  This  includes  a  complete 
set  of  carpenter's  tools,  a  forge  and  blacksmith's  outfit, 
and  the  various  small  tools  necessary  to  properly  care 
for  the  tractor  engine.  The  plan  at  Fig.  149  shows  a 
tentative  layout  that  may  be  followed  to  advantage. 
In  this,  the  workshop  is  provided  with  a  long  bench 
at  the  back  end,  a  portion  of  which  is  reserved  for  wood 


Power  Plant 


Fig.  150a. — Interior  View  of  Household  Workroom  in  Which 
Shafting  May  be  Run  From  Tractor  Housed  Alongside. 

work,  while  the  remainder  is  convenient  to  the  forge 
and  anvil.  An  8-foot  door  is  provided  so  any  farm  wagon 
or  other  appliance  may  be  run  into  the  building  when 
it  needs  repairing  and  be  worked  on  in  comfort.  While 
general  dimensions  are  given  these  and  the  arrangement 
of  tools  may  be  varied  to  suit  individual  requirements. 
A  more  complete  combined  tractor  house  and  work- 
shop is  outlined  in  plan  at  Fig.  150.     In  this  provision 


The  Modern  Gas  Tractor 


351 


<J=^ 


r=f 

1    1 

=4 

352  The  Modern  Gas  Tractor 

is  made  so  the  tractor  may  supply  power  to  either  of 
the  workshops,  one  of  which  is  disposed  at  each  side 
of  the  tractor  house.  The  equipment  of  the  repair 
shop  has  been  increased  by  the  addition  of  a  lathe  and 
emery  wheel  which  can  be  used  to  advantage  on  any 
farm  where  the  owner  or  employees  have  some  degree 
of  mechanical  skill.  In  addition  to  the  repair  shop, 
which  is  placed  at  the  right  of  the  tractor  house,  there 
is  a  home  workshop  in  which  various  machines  belong- 
ing to  the  dairy  or  laundry  are  installed  and  provided 
with  belts  so  that  they  may  be  run  by  power.  A  line 
of  shaft  passes  through  the  center  of  each  workshop 
and  is  belted  to  a  short  line  of  shaft  in  the  tractor  house. 
This  is  adapted  to  be  driven  either  by  a  gas  engine  of 
comparatively  low  power  which  is  installed  in  a  small 
power  house  added  on  to  the  tractor  shed,  or  it  may 
be  operated  by  belt  direct  from  the  tractor. 

When  the  traction  engine  is  at  work  in  the  field,  the 
small  gas  engine  will  supply  power  enough  to  turn 
the  shafting  and  run  any  one  or  two  of  the  machines 
in  either  shop,  though  when  the  tractor  is  used  for 
power  there  is  such  a  margin  that  all  the  machinery 
can  be  operated  simultaneously.  There  would  seldom 
be  a  time  when  all  of  the  machinery  would  be  working 
and  the  tractor  be  out  in  the  field  at  the  same  time, 
so  the  small  engine  which  is  of  4  or  5  horse-power  will 
prove  adequate  for  the  ordinary  everyday  tasks.  It 
will  be  noticed  that  the  line  shaft  from  the  home  work- 
shop projects  through  the  wall  and  is  belted  to  a  circular 
saw  which  is  housed  in  a  shed  or  lean-to  which  forms 
an  extension  of  the  home  workshop.  It  is  preferable 
to  house  the  saw  in  this  manner  instead  of  in  a  walled 
room  because  it  is  easier  to  handle  the  logs  to  be  sawed 
and  the  cut  pieces  with  the  saw  practically  out  in  the 


The  Modern  Gas  Tractor  353 

open.  At  the  same  time  some  degree  of  protection  is 
offered  by  the  roof  of  the  shed  and  when  enough  wood 
has  been  sawed  for  a  period  the  belt  may  be  removed 
from  the  pulleys  and  the  saw  from  the  arbor  and  both 
stored  away  while  the  saw  frame  may  be  covered  with 
a  piece  of  canvas  which  will  afford  sufficient  protection. 

The  view  at  Fig.  150- A  shows  the  interior  of  a  home 
workshop  in  which  the  power  plant  is  housed  in  the  same 
building  as  the  machinery  it  operates.  This  shows 
the  various  machines  which  can  be  conveniently  operated 
by  power  and  which  save  time  and  labor.  Obviously, 
the  shaft  could  be  extended  through  into  a  house  along- 
side in  which  the  tractor  could  be  run  when  it  had  done 
its  work  in  the  field  and  be  made  to  furnish  power  for 
this  shop  as  well  as  for  the  other  machinery  in  the 
repair  shop.  By  using  a  tractor  engine  in  this  manner 
through  the  winter  months,  it  is  kept  properly  limbered 
up  and  the  machine  is  always  ready  for  use.  If  the 
tractor  house  is  unheated  an  anti-freezing  compound 
may  be  used  in  the  radiator  or  cooling  system  and  no 
damage  can  result  when  the  temperature  is  low. 

Housing  a  tractor  in  this  manner  insures  that  it  will 
receive  attention  during  the  idle  period  as  it  is  an 
inducement  to  the  workmen  to  make  repairs  on  a 
machine  that  is  comfortably  housed,  whereas  they  would 
not  desire  to  work  around  the  same  machine  if  it  was 
in  the  open  and  exposed  to  the  elements.  The  view 
at  Fig.  151  shows  the  appearance  of  the  shop  and  tractor 
house  outlined  at  Fig.  150  when  viewed  from  the  front. 
Combination  structures  of  this  character  may  be  built 
by  using  concrete  blocks  or  reinforced  concrete  con- 
struction for  the  tractor  house  while  the  adjacent  shops 
may  be  made  more  lightly  from  lumber.  This  is  a  good 
combination,    as    the    tractor    house    is    fireproof    and 


354  The  Modern  Gas  Tractor 

wooden  structures  are  adequate  to  house  the  various 
household  and  repair  equipment.  A  hard  dirt  floor 
should  be  provided  in  the  tractor  house,  this  being 
sloped  either  toward  the  center  of  the  floor  or  to  one 
end  where  a  drain  should  be  placed  that  will  allow  any 
drippings  from  the  tractor  to  run  out. 

The  tractor  house  should  be  well  ventilated  in  order 
that  no  gasoline  fumes  can  accumulate  and  some  means 
should  be  provided  for  disposing  of  the  exhaust  of  the 
engine  so  this  will  be  directed  to  the  outer  air,  instead 
of  being  confined  in  the  tractor  house.  A  hood  of 
sheet  metal  may  be  placed  directly  over  the  exhaust 
pipes  so  the  exhaust  gases  will  be  directed  through  the 
roof  or  a  pipe  with  a  quickly  detachable  connection 
that  will  fasten  to  the  exhaust  pipe  of  the  engine  may 
lead  the  gases  to  a  muffler  if  it  is  desirable  to  reduce 
the  sound  of  the  escaping  exhaust.  A  good  muffler 
for  this  purpose  is  easily  and  cheaply  made  by  filling 
a  hogshead  with  large  stones  leaving  it  open  at  the  top 
and  connecting  the  exhaust  pipe  to  the  bottom.  The 
stones  will  break  up  the  exhaust  gases  and  muffle  the 
sound  so  that  it  will  not  be  objectionable.  A  cowl 
should  be  placed  over  the  hogshead  so  that  rain  cannot 
get  in  but  at  the  same  time  sufficient  opening  should 
be  left  around  the  edges  so  the  gases  will  escape  freely 
to  the  atmosphere. 

Fuel  Storage  Methods. — An  important  problem 
confronting  the  man  who  takes  care  of  either  his  own 
tractor  or  automobile  and  stores  it  in  a  special  motor 
house  in  close  proximity  to  a  residence  or  other  building 
is  that  of  gasoline  storage.  There  are  three  methods 
available.  A  very  dangerous  one  commonly  practiced 
is  to  keep  this  highly  inflammable  liquid  in  five  or  ten 
gallon  cans  in  the  tractor  house,  the  second  is  to  have 


The  Modern  Gas  Tractor 


Fig.  152. — Arrangement  of  Parts  of  Approved  and  Convenient 
Fuel  Storage  System  for  Tractor  House. 


356 


The  Modern  Gas  Tractor 


a  separate  structure  especially  for  gasoline  storage, 
while  the  third  is  to  install  an  underground  tank,  there 
being  several  excellent  types  in  the  market.  The  last 
mentioned  is  to  be  preferred  from  the  viewpoint  of  safety, 
though  the  average  farmer  does  not  take  kindly  to 
this  because  of  what  is  considered  the  high  first  cost 
of  even  a  simple  storage  outfit  of  first-class  construc- 
tion.    Storing  the  gasoline  in  cans  is  not  desirable  for 


Gasoline  Supply  Pipe 


Filler  Cap . 


Section  View 


/  /.  /  /  /    /     /      ''  "  /    /  /  -/- 


Fig.  152a. — A  Simple  Home-made  Underground  Gasoline  Stor- 
age System  That  is  Economical  and  Easy  to  Make. 

several  reasons,  chief  among  which  is  that  storing  the 
fuel  in  this  manner  makes  for  considerable  loss  by 
evaporation  and  by  leakage  or  spilling  when  filling 
tanks  directly  from  the  container.  An  underground 
storage  outfit  of  excellent  construction  and  of  simple 


The  Modern  Gas  Tractor  :{.">7 

design,  which  should  not  prove  costly,  is  shown  at 
Fig.  152.  In  this  the  fuel  is  stored  in  a  large  tank  buried 
underground  outside  of  the  garage  or  tractor  house, 
while  a  hand  operated  pump  of  the  suction  type  is  inside 
the  shelter  and  protected  from  the  elements.  At  Fig. 
152-A  an  underground  gasoline  storage  outfit  which 
can  be  installed  at  low  cost  and  made  by  any  one  of 
average   mechanical   intelligence   is   outlined. 

This  consists  of  an  air-tight  copper  or  steel  tank, 
well  coated  with  asphaltum  paint,  preferably,  though 
a  galvanized  iron  container  can  be  used  if  desired. 
The  construction  should  be  such  that  the  tank  will 
resist  air  pressures  up  to  40  or  50  pounds  per  square 
inch.  Three  spuds  are  placed  in  the  top  of  the  tank, 
one  to  take  two-inch  standard  iron  pipe,  the  others 
to  fit  one-half  and  one-eighth  gas  pipe  respectively. 
A  two-inch  pipe  cap,  to  which  a  piece  of  one-half 
by  one-quarter  inch  bar  stock  is  attached  by  machine 
screws  or  rivets,  is  used  for  a  filler  cap  at  the  end  of 
the  piece  of  large  pipe.  This  is  cut  of  sufficient  length 
so  that  the  tank  can  be  buried  underground  below  frost 
line  and  still  leave  four  or  five  inches  of  pipe  projecting 
above  the  surface  after  the  hole  in  which  the  tank 
was  placed  is  filled. 

A  special  reducing  fitting  is  made  to  fit  the  spud, 
tapped  one-half  inch  pipe  size,  this  to  take  a  piece 
of  one-quarter  inch  pipe,  which  extends  to  about  an 
inch  from  the  bottom  of  the  tank  and  projects  above 
the  surface  of  the  reducing  bushing.  A  standard  ell 
is  then  screwed  in  place  and  the  piping  continued  as 
shown  in  sketch.  A  piece  of  one-eighth  gas  pipe  runs 
from  the  other  spud  to  a  T  piece  from  which  a  branch 
extends  to  an  air  pressure  gauge,  and  in  which  is 
placed  a  short  piece  of  pipe  having  a  ball  check  fitting 


358 


The  Modern  Gas  Tractor 


or  the  usual  universal  tire  valve.  At  the  end  of  the 
one-quarter  inch  pipe,  which  runs  up  inside  the  motor 
house,  is  placed  a  ground  shut-off  fitting,  to  which  a 
piece  of  rubber  hose  ten  or  twelve  feet  long  is  attached. 
It  is  advisable  to  make  both  the  one-quarter  and  one- 
eighth  inch  pipe  lines  of  brass,  and  to  solder  all  joints 


Fig.  152b. — Bowser    Underground    Fuel    Storage    System    for 
Automobiles  or  Tractors. 

as  they  are  made,  to  insure  absolute  tightness  at  all 
points  and  eliminate  all  possibilities  of  leakage.  The 
small  petcock  placed  below  the  valve  fitting  is  to 
be  closed  except  when  it  is  desired  to  take  a  gauge 


The  Modern  Gas  Tractor  359 

reading  or  when  an  ordinary  foot  pump  is  coupled 
to  the  valve  to  compress  more  air  in  the  tank.  This 
fitting  when  closed  prevents  leakage  of  air  through 
the  check  valve,  which  might  result  if  this  was  depended 
upon  to  retain  the  compressed  air  in  the  container. 

The  handle  on  the  filler  cap  is  convenient  in  filling 
the  container  as  it  provides  leverage  and  makes  easy 
the  removal  of  the  cap  from  the  pipe.  This  may  be 
protected  by  a  strong  wooden  box,  with  a  hinged 
cover,  provided  with  a  hasp  and  padlock  to  prevent 
tampering  with  the  contents.  The  tank  may  be  of 
any  desired  capacity,  but  one  holding  about  200  gal- 
lons will  answer  the  requirements  of  the  average  tractor 
operator.  The  filler  cap  should  seat  against  a  piece  of 
soft  packing  to  insure  an  air  tight  joint  on  the  fill- 
ing pipe.  The  tank  should  be  placed  as  close  to  the 
wall  of  the  tractor  house  as  possible  to  simplify  piping. 
After  the  container  is  filled  with  fuel  to  about  seven- 
eighths  its  capacity  to  leave  an  air  space,  an  ordinary 
foot  pump  is  coupled  to  the  air  valve  in  the  pressure 
pipe  and  air  supplied  to  the  tank  until  the  gauge  indi- 
cates a  pressure  of  15  or  20  pounds  a  square  inch  on 
top  of  the  liquid.  In  filling  a  tractor  tank,  it  is  merely 
necessary  to  place  the  end  of  the  rubber  hose  in  the 
tank  opening  and  turn  on  the  supply,  and  after  suffi- 
cient fuel  is  drawn  the  shut-off  fitting  may  be  closed. 
As  the  supply  of  gasoline  becomes  less,  more  air  should 
be  forced  into  the  main  container.  The  installation 
is  not  costly,  and  the  material  needed,  with  the  possible 
exception  of  the  tank,  can  be  obtained  in  almost  any 
town  or  village,  and  its  simplicity  and  utility  will  be 
appreciated  by  the  practical  farmer.  All  fittings  are 
indicated  in  the  drawing  and  there  should  be  no  diffi- 
culty in  assembling  the  outfit. 


3G0  The  Modern  Gas  Tractor 

Tools  and  Equipment  for  Care  of  Tractor. — The 

farmer  who  intends  to  take  care  of  this  own  tractor 
or  one  who  has  several  of  these  machines  will  find  need 
for  a  number  of  tools  of  a  slightly  different  character 
from  those  generally  used  in  repairing  farm  implements. 
A  set  of  small  tools  most  likely  to  be  used  should  be 
carried  on  every  tractor,  as  often  repairs  of  a  minor 
nature  must  be  made  in  the  field.  In  the  illustration 
'Fig.  153)  a  comprehensive  outfit  of  small  tools  and 
devices  that  will  be  found  especially  valuable  in  making 
repairs  for  the  tractor  engines  or  transmission  system 
are  outlined.  The  tool  roll  contains  an  assortment  of 
tools  that  are  more  generally  used  and  is  a  modified 
form  of  the  tool  kit  generally  supplied  for  automobile 
repairing.  The  only  difference  between  the  tools  is 
that  these  are  larger  and  more  substantial  in  order  to 
handle  the  more  rugged  parts  of  the  tractor  mechanism. 
The  tool  roll  shown  contains  all  necessary  wrenches, 
pliers,  screw  drivers,  punches,  drift  pins,  chisels  and 
files,  as  well  as  miscellaneous  supplies  necessary  to 
make  ordinary  repairs.  r 

In  addition  to  the  tools  outlined  a  small  bench  vise 
that  can  be  attached  to  the  step  or  tool  box  cover  of 
the  tractor  will  be  found  of  considerable  value.  The 
large  file  assortment  may  be  kept  at  the  workshop  for 
use  in  making  more  extended  repairs.  This  is  true  also 
of  the  carbon  scrapers,  the  valve  spring  lifter  and  the 
hand  drill.  The  hacksaw,  hand  vise  and  tinner's  snips 
occupy  but  little  room  and  can  be  conveniently  stored 
away  in  the  tractor  tool  box.  The  blow  torch  will  be 
found  very  desirable  in  providing  a  source  of  heat  for 
the  soldering  iron  and  for  loosening  rusted  on  nuts 
and  for  many  other  purposes  that  will  suggest  themselves. 
Among  the   general   supplies   that  should   be   included 


The  Modern  Gas  Tractor 


361 


302  The  Modern  Gas  Tractor 

in  the  equipment  are  spare  spark  plugs  for  the  motor, 
a  few  feet  of  primary  and  secondary  electric  wire,  ma- 
terial to  make  the  various  gaskets  and  packings  used 
on  the  engine,  a  quantity  of  cotton  waste  or  old  rags, 
an  emergency  supply  of  cylinder  oil  for  the  lubricator 
and  hard  grease  for  the  grease  cups.  The  other  sup- 
plies or  spare  parts  needed  will  vary  with  the  type  of 
tractor  and  the  distance  it  is  to  be  operated  from  a 
base  of  supply. 

The  writer  has  made  mention  of  the  fact  that  an  out- 
fit of  blacksmith's  tools  may  be  obtained  at  relatively 
small  cost.  As  these  enter  largely  into  the  care  of  the 
tractor  and  auxiliary  appliances  it  may  be  pertinent 
to  enumerate  the  contents  of  a  complete  blacksmith's 
outfit  which  is  illustrated  at  Fig.  154  and  which,  can 
be  purchased  for  $35  to  $40.  This  consists  of  a  60- 
pound  anvil  with  tool  steel  face;  a  35-pound  wrought 
iron  blacksmith's  vise;  a  portable  lever  forge,  provided 
with  a  compact  blower  for  supplying  draft,  and  a  two- 
speed  self-feed  post  drill  which  takes  up  to  half  inch 
round  shank  drills  and  will  drill  to  the  center  of  a  twelve- 
inch  circle.  The  miscellaneous  small  tools  include  a 
die  stock  and  dies,  a  set  of  standard  taps,  one  hot  cutter, 
one  cold  cutter,  a  hardie,  a  pair  of  flat-lip  tongs,  one 
pair  of  pincers,  one  farrier's  knife,  seven  drill  bits,  one 
farrier's  hammer,  one  hand  hammer  and  a  monkey 
wrench. 

A  few  other  tools,  such  as  a  medium  weight  sledge 
hammer,  a  more  complete  assortment  of  tongs,  two  or 
three  rasps,  a  set  of  heavy  files,  and  an  assortment 
of  standard  bolts  and  nuts,  as  well  as  blanks  which 
may  be  threaded  as  required,  will  be  found  valuable. 
The  stock  needed  may  be  purchased  at  small  cost  and 
will  include  various  sizes  of  round,  flat  and  square  bar 


The  Modern  Gas  Tractor 


363 


3(i4 


The  Modern  Gas  Tractor 


iron  and  steel.  All  the  odds  and  ends  of  iron  or  steel, 
as  well  as  cast-off  bolts,  tie-bars,  turn  buckles,  iron 
hoops,  etc.,  that  ordinarily  go  to  waste,  may  be  picked 
up  and  put  in  a  stock  box  with  the  assurance  that  they 
will  be  found  useful  at  some  future  date. 

No  workshop  will  be  complete  without  a  set  of  wood 
working  tools  and  very  fortunately  a  very  practical 
outfit  can  be  purchased   at   comparatively  small  cost. 


Fig.  155. — Complete  Set  of  Carpenter's  Tools  a  Useful  Addi- 
tion to  Farm  Repair  Shop  Equipment. 

Wood  working  tools  are  not  only  necessary  in  the  farm 
workshop  but  are  of  obvious  utility  in  making  repairs 
incidental  to  the  upkeep  of  buildings,  fences,  and  the 
erection  of  new  structures.  A  very  convenient  outfit 
for  use  around  the  farm  or  shop  is  shown  at  Fig.  155 


The  Modern  Gas  Tractor  :!i>.~> 

and  can  be  purchased  for  .$12  to  $15.  It  consists  of 
the  following  tools:  One  22"  hand  saw,  one  6"  try 
square,  one  2'  rule,  one  pair  5J^"  combination  pliers, 
one  10"  bit  brace,  four  auger  bits,  one  each  size  ^", 
Vi'  M">  and  1";  five  gimlet  bits,  one  steel  hammer,  one 
8"  draw  knife,  one  double  cutter  spoke  shave,  one  5" 
steel  blade  screw  driver,  two  socket  chisels,  one  jack 
plane,  one  5%"  iron  block  plane  and  a  carpenter's  pencil. 
A  plumb  bob  and  chalk  line,  nail  set,  level  and  a  large 
steel  square  can  be  purchased  to  complete  this  outfit 
at  slight  added  expense.  The  hardware  necessary,  such 
as  nails,  screws,  staples,  locks,  hinges,  etc.,  can  be 
purchased  as  required  and  soon  enough  of  these  supplies 
are  left  over  when  purchases  are  made  from  time  to 
time  so  a  very  useful  stock  of  miscellaneous  small  hard- 
ware accumulates  without  its  cost  being  so  apparent 
as  would  be  the  case  if  everything  that  was  thought 
desirable  was  purchased  outright. 


CHAPTER  X. 

TRACTION   ENGINE  TROUBLES  AND  ELIMINATION. 

Location  of  Defects  and  Remedies — Loss  of  Power — Poor 
Compression — Carbon  Deposits — Valve  Grinding — Timing 
Valves — Care  of  Piston  and  Rings — Noisy  Operation — 
Adjusting  Bearings — Mixture  Troubles — Ignition  System 
Derangements — Cooling  and  Lubrication  Group  Faults — 
Running  Gear  Derangements— Tractor  Hitches — Utility 
and  Uses  of  Modern  Gas  Tractor — Homemade  Gas  Trac- 
tors— Auto  Tractor  Attachment — Future  Possibilities. 

Location  of  Defects,  and  Remedies. — The  de- 
rangements that  interfere  with  satisfactory  tractor  opera- 
tion may  exist  in  either  the  tractor  power  plant  which 
includes  the  engine  and  auxiliary  groups  or  in  the 
running  gear  assembly  in  which  the  clutches,  transmis- 
sion, driving  and  differential  gearing,  as  well  as  frame, 
wheels  and  axles  are  included.  The  troubles  with  the 
power  plant  are  the  most  difficult  to  detect  because 
there  are  a  number  of  different  conditions  that  may 
produce  the  same  symptoms.  Running  gear  faults, 
as  a  rule,  are  easily  located  because  they  are  usually 
due  to  some  loose  or  damaged  part  that  may  be  easily 
noticed   on  inspection. 

One  who  is  familiar  with  mechanical  construction  and 
practical  operation  of  tractors  will  have  no  difficulty 
in  tracing  common  motor  troubles  to  their  source,  but 
while  the  expert  readily  recognizes  the  symptoms  which 
show  derangement  of  the  various  power  plant  components 

366 


The  Modern  Gas  Tractor 


367 


the  average  farmer  or  tractor  operator  is  apt  to  waste 
a  lot  of  time  and  energy  in  trying  to  locate  trouble 
unless  he  does  so  by  a  systematic  search  for  defects. 
The  internal  combustion  motor  or  gas  engine,  which 
is  utilized  as  a  power  plant  on  practically  all  gas  tractors 
and  which  is  clearly  shown  in  Figs.  156  and  157,  is 
composed  of  a  number  of  distinct  groups  which  have 
been    previously    described    in    detail.      These    various 


Fig.  156. — Power   Plant   of   Phoenix    Tractor   Showing   Water 
Pump.    Governor    Assembly    and    Ignition    Magneto. 

auxiliary  devices  are  closely  related  to  each  other 
and  defective  operation  of  any  one  of  these  may  seriously 
affect  the  power  plant  or  stop  it  altogether. 

The   careful   tractor   driver   will   always   inspect   the 
motor  and  other  points  of  the  mechanism  liable  to  de- 


3GS 


The  Modern  Gas  Tractor 


rangement  before  starting  on  a  run  of  any  consequence, 
and  if  inspection  is  carried  out  in  a  systematic  manner 
and  any  loose  nuts,  wires  or  other  fastenings  are  given 
attention  it  is  seldom  that  irregular  operation  will  be 
due  to  any  broken  parts.  The  natural  wear  and  the 
depreciation  which  it  causes  occur  slowly  and  when  parts 
begin  to  deteriorate  sufficient  warning  is  always  given 


Fig.  157.— Valve  Side  of  Phoenix  Four  Cylinder  Tractor  Motor 
Showing  Crankcase  Inspection  Plates,  Inlet  and  Exhaust 
Manifolds  and  Carburetor. 

so  that  repairs  may  be  made  promptly,  and  thus  serious 
derangement  is  prevented. 

The  main  troubles  with  the  power  plant  are  loss  of 
power,  irregular  action,  overheating,  and  noisy  opera- 
tion.    The  first  usually  denotes  some  fault  in  the  piston 


The  Modern  Gas  Tractor 


369 


rings  or  valves  of  the  engine  and  is  due  primarily  to 
poor  compression.  Irregular  operation,  which  is  the 
condition  that  exists  when  cylinders  do  not  fire  regu- 
larly, is  nearly  always  the  result  of  defects  in  the  gas 
supply  system  or  the  ignition  appliances.  Overheating 
invariably  denotes  inadequate  lubrication  or  failure  of 
the  ccoling  system.  Noisy  operation  can  always  be 
accepted  as  a  condition  due  to  mechanical  wear. 


Fig.  158. — Side  View  of  Bates  Gas  Tractor  Showing  Accessi- 
bility of  Power  Plant  When  Automobile  Type  Motor  Hood 
is  Raised. 

Loss  of  Power. — While  loss  of  power  is  usually  a 
condition  that  can  be  ascribed  to  poor  compression  it 
will  result  indirectly  if  any  of  the  other  faults  are  evident. 
Obviously,  if  an  engine  is  missing  explosions  and  is 
not  firing  regularly  its  power  will  be  reduced  materially 
and  thus  the  condition  of  ''skipping"  or  "missing  fire" 
as  it   is  called  will  produce  loss  of  power  indirectly.     If 


370 


The  Modern  Gas  Tractor 


the  engine  is  overheated  so  the  various  parts  are  running 
with  considerable  friction  there  will  be  a  loss  of  power 
because  of  the  increased  internal  load  in  the  motor 
itself.  Overheating  may  be  directly  caused  by  failure 
of  the  oil  supply  in  which  case  the  coasequences  are 
apt  to  be  serious  unless  the  motor  is  stopped  as  soon 
as  this  defect  is  apparent.  Troubles  with  the  cooling 
system  are  easily  determined  by  the  steam  which  issues 
from  the  radiator  or  cooling  tank. 


Fig.   1.58  a. -^Showing    Accessibility,  of   Power  Plant   on   Holt 
Caterpillar  Tractor. 

Tractor  power  plants  are  generally  housed  in  an 
accessible  manner,  if  they  are  under  a  hood  or  bonnet, 
as  outlined  at  Fig.  158,  or  may  be  easily  reached  as 
ordinarily  mounted  in  unprotected  positions  on  the 
tractor  frame.  The  power  plant  shown  at  Fig.  159  has 
been  photographed  in  position  on  the  frame  with  other 
parts  removed  in  order  to  show  clearly  the  method  of 
placing  a  typical  tractor  motor  and  the  auxiliary  devices 


The  Modern  Gas  Tractor  371 

upon  which  its  operation  depends.  The  location  and 
method  of  drive  of  the  magneto  which  forms  the  igni- 
tion system  and  that  of  the  mechanical  oiler,  which 
supplies  the  engine  with  lubricant,  is  clearly  outlined. 
The  valve  springs  are  placed  at  the  top  of  the  cylinders 
and  are  easily  reached  when  it  is  desired  to  relieve  the 
valves  of  their  tension  so  that  these  members  may  be 
ground.  The  centrifugal  governor  and  the  linkage  by 
which  it  controls  the  throttle  valve  are  also  clearly 
outlined.  Attention  is  called  to  the  inspection  plates 
on  top  of  the  engine  base  through  which  the  interior 
portions  of  the  crank  case  may  be  easily  inspected.  These 
plates  are  readily  detachable  by  loosening  a  bolt  that 
holds  them  in  place  by  a  clamp  bar,  the  ends  of  which 
bear  on  the  center  portion  of  two  plates. 

If  it  is  desired  to  remove  the  cylinders,  the  first  step 
is  to  take  off  the  exhaust  and  intake  manifolds,  then 
the  cylinder  pair  may  be  pulled  off  of  the  engine  base 
by  removing  the  nuts  that  hold  it  in  place.  The  valves 
may  be  ground  without  removing  the  cylinders,  and  in 
fact  all  working  parts  of  this  motor  may  be  reached 
without  taking  the  lower  portions  of  the  crank  case 
or  engine  bed  from  its  position  on  the  tractor  frame. 
If  adjustments  are  necessary  to  the  bearings  of  thecrank 
shaft,  the  top  half  of  the  diagonally  divided  crank  case 
may  be  removed  without  difficulty  by  loosening  a  few 
oil  pipes  and  the  connecting  link  between  the  governor 
and  the  throttle  chamber.  When  this  top  plate  is 
removed  the  entire  interior  of  the  crank  case,  including 
the  cam  shaft,   is  open  for  inspection. 

The  point  of  accessibility  is  one  that  is  given  special 
prominence  in  the  design  of  tractor  power  plants,  much 
more  so  than  is  the  case  in  the  small  gas  engines  used 
for  automobile  propulsion.     This  is  on  account  of  the 


372 


The  Modern  Gas  Tractor 


large  size  cf  the  tractor  engine  parts  and  the  difficulty 
which  obtains  in  handling  them  without  proper  facili- 
ties. As  an  example  of  a  construction  that  permits  maxi- 
mum accessibility,  the  illustration  at  Fig.  160  is  pre- 
sented. This  shows  a  workman  removing  the  piston 
from  the  interior  of  a  gas  tractor  cylinder  without 
removing  the  latter  from  the  engine  base  or  taking  the 
engine    bed    from    its    position    on    the    tractor    frame. 


EXHAUST  FIPE5 


THROTTLE  CilAMftEff 


MAGNETO 

i       •  ^ 

{jl/FLYBALL  GOVERNOR 
1     NT  nnfflft     MECHANICAL 

'  **  ^B       OILER 

INSPECTION 
PLATE 


Fig.  159. — Power  Plant  of  "Twin  City  25"  Gas  Tractor  Show- 
ing Accessibility  of  Auxiliary  Parts.  Valves  and  Valve 
Springs  and   Crankcase   Interior   Inspection   Plates. 

Most  traction  engine  designers  endeavor  to  have  all 
parts  accessible  as  this  is  one  of  the  first  things  that 
the  experienced  tractioneer  looks  for  when  purchasing 
a  new  machine. 

A  breakdown  in  the  field  is  not  always  serious  if  the 
parts  can  be  readily  reached,  but  at  the  other  hand,  it 


The  Modern  Gas  Tractor 


373 


may  mean  the  expenditure  of  considerable  time  and 
money  if  the  entire  engine  has  to  be  dismantled  every 
time  the  interior  mechanism  is  out  of  order.  There 
are  some  automobile  engines  where  it  is  practically  im- 
possible to  reach  the  pistons  without  taking  the  cylinders 
off  of  the  engine  bed  and  where  the  entire  engine  must 
be  taken  apart  to  get  at  the  main  bearings  of  the  crank- 
shaft or  the  bushings  in  the  big  ends  of  the  connecting 


Fig.  160. — Showing  How  a  Piston  of  Gas  Traction  "Big  Four" 
Engine  May  be  Removed  From  Cylinder  to  Inspect  Rings 
and  Remove  Carbon  Deposits  From  Piston  Top. 

rods.  This  is  not  tolerated  by  the  expert  gas  tractor 
operator,  and  the  factor  of  accessibility  of  components 
alone  may  make  or  prevent  the  sale  of  a  machine. 

Poor  Compression. — If  the  engine  is  losing  power 
and    the   power   loss   is  not   accompanied   by   skipping, 


374  The  Modern  Gas  Tractor 

overheating,  or  noisy  operation,  it  is  due  to  poor  com- 
pression. This  results  from  conditions  inside  or  outside 
of  the  cylinders  that  will  allow  leakage  of  gas  from  the 
interior.  Gas  may  escape  through  defective  valve 
operation  caused  by  the  valves  not  seating  properly 
or  being  out  of  time.  If  the  valve  system  is  all  right 
the  trouble  is  generally  due  to  faulty  piston  rings  or 
worn  or  scored  cylinders.  The  method  of  testing  for 
poor  compression  is  simple,  consisting  of  cranking  the 
engine  without  the  ignition  system  being  turned  on 
and  with  compression  relief  cocks  closed.  If  the  engine 
turns  over  easily  and  no  appreciable  resistance  is  felt, 
it  is  invariably  due  to  a  loss  of  gas  from  one  or  more 
of  the  cylinders.  If  it  is  a  multiple  cylinder  engine 
the  defective  member  may  be  easily  determined  by 
cranking  over  the  motor  with  all  of  the  compression 
cocks,  except  one,  open.  Each  cylinder  is  tested  in 
turn  and  the  thing  to  remember  is  to  keep  the  com- 
pression cock  in  the  cylinder  that  is  to  be  tested  closed, 
while  the  others  are  left  open  so  that  the  engine  can  be 
turned  with  minimum  resistance.  The  cylinders  that 
have  good  compression  will  offer  a  decided  resistance  to 
turning  the  crankshaft,  while  those  in  wh'ch  compres- 
sion is  weak  will  permit  one  to  turn  the  crank  very  easily. 
If  compression  is  poor  the  first  thing  to  do  is  to  inspect 
the  external  parts  which  may  be  easily  reached.  This 
means  looking  for  a  leak  at  valve  chamber  caps,  spark 
plug  gasket,  or  blown  packing  between  cylinder  and 
cylinder  head,  if  that  construction  is  employed.  Other 
causes  are  broken  valve  springs,  sticking  or  bent  valve 
stems,  valve  plunger  stuck  in  guide,  loss  of  clearance 
between  valve  stem  end  and  top  of  valve  operating 
plunger  (usually  caused  by  loose  adjusting  screw  which 
has  worked  up  and  kept  the  valve  from  seating)  or  a 


The  Modern  Gas  Tractor  375 

defective  priming  cock.  Some  of  the  defects  of  the 
internal  parts  which  may  be  looked  for  are  a  broken 
valve,  a  warped  valve  head,  dirt  under  valve  head,  which 
prevents  valve  from  seating,  burnt  or  pitted  valve 
seat  or  valve  head,  cracked  piston  head  or  cylinder 
(rarely  occurs),  broken  piston  rings,  piston  ring  slots 
in  line,  loss  of  piston  ring  elasticity  or  spring,  or  piston 
rings  gummed  in  the  piston  grooves.  The  piston  and 
cylinder  walls  may  be  badly  scored  by  defective  lubri- 
cation or  a  deep  groove  may  have  been  cut  in  the  cylin- 
der by  a  loose  wrist  pin  which  allows  the  gas  to  blow 
by  very  easily. 

Carbon  Deposits. — One  of  the  fertile  causes  of 
general  motor  inefficiency  and  one  which  often  con- 
tributes to  loss  of  power,  as  well  as  noisy  operation, 
is  the  deposit  of  carbon  that  accumulates  in  the  com- 
bustion chamber.  These  deposits  result  from  burnt 
cylinder  oil  and  sometimes  from  excessively  rich  mixture, 
and  are  more  apt  to  exist  on  motors  operating  on  low 
grade  fuel  such  as  kerosene  or  distillate,  than  in  gasoline 
engines  where  combustion  is  more  perfect.  These 
deposits  accumulate  on  the  piston  top  and  in  the  in- 
terior of  the  combustion  head  and  valve  chamber.  They 
interfere  with  correct  valve  operation  by  gumming  up 
the  valves  and  prevent  a  full  charge  from  reaching  the 
motor,  as  well  as  retarding  the  prompt  expulsion  of 
burnt  gases  by  building  up  around  the  valves. 

The  deposits  in  the  cylinder  head  may  cause  trouble 
owing  to  some  projecting  particle  remaining  incandes- 
cent from  the  heat  of  a  previous  explos'on  and  firing 
the  fresh  charge  prematurely.  Carbon  deposits  always 
produce  loss  of  power,  but  their  presence  is  usually 
clearly  indicated  by  a  pronounced  knocking  or  pounding 
noise.     The  only  remedy   for  this  defective  condition 


;>7(i  The  Modern  Gas  Tractor 

is  to  remove  them  from  the  engine  interior.  This  is 
done  by  scraping  away  the  material  with  small  hoe- 
form  steel  scrapers  that  may  be  Inserted  through  the 
holes  left  when  the  valve  chamber  caps  are  removed 
or  by  removing  the  cylinder  head  if  the  construction 
permits.  This  is  one  of  the  marked  advantages  of  the 
detachable  head  design.  The  head  may  be  removed 
without  disturbing  the  rest  of  the  motor  and  the  de- 
posits of  carbonaceous  substance  may  be  scraped  from 
both  cylinder  head  and  piston.  If  the  deposits  are  of 
long  standing  it  wi'l  be  necessary  to  dismantle  the  motor 
in  order  to  reach  them  and  secure  their  positive  removal. 

This  accumulation  may  be  prevented  by  careful  super- 
vision of  the  amount  of  oil  supplied  the  motor,  making 
sure  that  it  is  never  in  excess  of  the  actual  requirements, 
using  only  the  best  grades  of  cylinder  oil  having  a  high 
fire  test,  and  by  careful  regulation  of  the  mixture  to 
insure  that  the  fuel  and  air  proportions  will  be  those 
that   will   burn   without   leaving   a  residue. 

These  deposits  may  be  reduced  to  some  extent  by 
injecting  three  or  four  tablespoonfulls  of  kerosene  into 
the  cylinders  at  the  end  of  a  day's  run,  through  the 
priming  cocks.  This  softens  the  deposit  which  has  ac- 
cumulated during  the  day  and  when  the  engine  is  started 
up  the  next  mormng  the  dissolved  carbon  will  be  ejected 
through  the  exhaust  as  it  will  be  carried  out  by  the 
burnt  gases.  The  soft  deposit  is  not  difficult  to  cope 
with,  and  in  fact,  various  chemical  carbon  removers 
are  advertised  quite  extensively  which  will  remove  it 
without  making  it  necessary  to  take  the  motor  apart, 
provided  the  accumulations  are  not  of  too  long  stand- 
ing. The  hard,  thoroughly  baked  on  carbon  can  only 
be  removed  by  mechanical  means. 

Valve  Grinding. — The  most  common  cause  of  lost 


The  Modern  Gas  Tractor 


::tt 


compression  is  leaky  valves,  and  this  condition  material- 
izes on  even  the  best  constructed  traction  engine.  This 
is  one  point  that  requires  periodical  attention,  and  as 
a  rule  the  first  thing  done,  if  the  engine  lacks  power, 
is  to  grind  in  the  valves  to  a  new  seating.  The  inlet 
valves  do  not  need  grinding  as  often  as  the  exhausts 
do,  but  they  are  generally  refitted  at  the  same  time 
that  the  exhaust  members  are  ground  to  a  new  seat. 
When  a  valve  needs  grinding  the  defective  conditions 
that  make  this  necessary  are  apparent  at  a  glance. 


Fig.  161. — How   Valve   Spring   and   Valve   May   be    Removed 
From  Gas  Tractor  Engine  Cylinder. 

The  first  step  when  valves  are  suspected  is  to  remove 
them  from  the  cylinder.  The  method  of  doing  this  is 
clearly  outlined  at  Fig.  161.  It  is  necessary  to  release 
the  valve  spring  pressure  sufficiently  so  the  key  which 
keeps  the  collar  against  the  lower  end  of  the  valve  spring- 
in  place  may  be  withdrawn  from  the  valve  stem.  The 
method  of  doing  this  is  shown  at  A.  The  first  opera- 
tion is  to  remove  the  valve  cap,  then  the  manifolds  may 
be  taken  from  the  motor.     The  valve  head  is  then  kept 


378 


The  Modern  Gas  Tractor 


in  place  by  pressing  down  on  it  with  a  screw  driver 
and  the  valve  spring  is  raised  either  by  means  of  a 
special  valve  spring  lifter  or  by  using  an  end  or  S  wrench 
or  any  other  fork  form  tool  that  will  raise  the  valve 
spring  without  touching  the  valve  stem.  After  the 
pin  or  key  is  withdrawn  from  the  valve  stem,  the  valve 
may  be  easily  lifted  from  the  cylinder,  as  shown  at 
Fig.   161-B. 

The  method  of  valve 
grinding  is  simple  and 
one  way  of  accomp- 
lishing this  is  shown 
at  Fig.  162.  Befcre 
the  valve  is  replaced 
in  the  cylinder  the 
stem  is  thoroughly 
cleaned  by  means  of 
emery  cloth  and  all 
gummed  oil  is  cleaned 
out  of  the  valve  stem 
guides.  A  light  spring 
is  placed  between  the 
valve  head  and  the 
end  of  the  valve  stem 
guide  in  order  to  raise 
it  from  its  seat  when 
pressure  on  the  grind- 
ing tool    is    relieved. 


VALVE   SEAT 

MOTE.    LIGHT  SPRING.    FOR 
LIFTING  VALVE  OFF  SEAT 

WHEN  6,»IN0INC 


Fig.  162.— Method  of  Using  Bit  Brace 
and  Screwdriver  Bit  in  Grinding 
Valves. 


Special  and  somewhat  costly  valve  grinding  tools  have  been 
devised,  and  while  these  members  are  thoroughly  practi- 
cal, a  very  efficient  and  satisfactory  appliance,  which 
is  almost  universally  used,  is  the  ordinary  bit  brace. 
A  screwdriver  bit  is  made  to  turn  the  valve,  provided 
that  the  head  is  properly  slotted  to  receive  this  form 


The  Modern  Gas  Tractor  :!7!) 

of  tool.  Sometimes  the  valve  head  is  provided  with 
two  holes,  and  is  then  turned  by  a  simple  forked  tool, 
which  may  be  easily  hammered  up  to  shape  so  it  will 
fit  the  bit  stock. 

The  faces  of  the  valve  and  the  valve  seat  are  smeared 
with  a  mixture  of  emery  and  oil  made  into  a  thick 
paste.  If  the  valve  surfaces  are  deeply  scored  or  pitted 
it  will  be  necessary  to  start  grinding  with  a  medium 
grade  emery.  In  grinding  only  sufficient  pressure  to 
keep  the  valve  against  the  seat  is  used  and  this  is  relieved 
from  time  to  time  in  order  that  the  valve  may  be  lifted 
from  its  seat  by  the  coil  spring  beneath  it.  Valves 
are  not  ground  with  a  continuous  rotary  motion.  The 
oscillating  motion  that  would  result  if  the  bit  stock 
was  turned  nearly  a  complete  revolution  and  then  back 
around  again  is  better,  lifting  the  valve  from  the  seat 
frequently  to  prevent  the  accumulation  of  little  balls 
of  emery  which  may  score  the  seat  quite  badly.  Too 
much  pressure  will  also  do  more  harm  than  good.  The 
valve  should  be  taken  from  the  cylinder  and  the  valve 
head  and  seat  thoroughly  cleaned  with  gasoline.  New 
abrasive  should  be  used  each  time  the  valve  is  replaced 
for  grinding. 

After  most  of  the  roughness  has  been  smoothed  down 
and  the  valve  head  and  seat  begin  to  have  an  even  ap- 
pearance which  is  an  indication  of  a  smooth  surface, 
the  mixture  of  medium  grade  emery  and  oil  may  be 
replaced  by  one  of  flour  emery,  crocus,  or  ground  glass, 
which  may  be  mixed  with  kerosene,  instead  of  the  heavier 
lubricating  oil.  These  make  fine  mixtures  for  polishing 
valve  seat.  When  the  valve  has  been  properly  ground 
it  will  be  smooth  and  have  a  bright  ring  all  around 
its  face.  The  valve  seat  will  also  show  bright.  An 
important  precaution  to  observe  when  grinding  valves, 


380  The  Modern  Gas  Tractor 

especially  on  horizontal  motors,  is  that  none  of  the 
abrasive  reaches  the  interior  of  the  engine  cylinder. 
This  is  easily  done  by  blocking  the  port  or  passage 
between  the  valve  and  combustion  chamber  with  a  wad 
of  cloth,  to  which  a  string  is  attached  so  it  may  be 
withdrawn  from  the  cylinder  without  trouble  in  case 
it  should  become  dislodged  from  its  position  and 
fall  in. 

Timing  Valves. — When  the  grinding  process  is 
completed  and  the  valve  springs  have  been  replaced, 
it  will  be  well  to  see  that  the  valves  are  timed  properly 
before  the  manifolds  are  put  back.  An  important 
point  to  observe  is  that  the  proper  amount  of  clearance 
between  the  end  of  the  valve  stem  and  the  plunger  is 
retained.  •  During  the  process  of  grinding  it  may  be 
possible  to  bed  the  valves  down  enough  so  that  the 
stems  will  project  farther  down  and  bear  against  the 
valve  plunger  before  the  valve  head  seats  in  the  valve 
chamber.  After  valves  are  ground  it  is  good  practice 
to  go  over  the  engine  timing  carefully  and  verify  it. 
The  flywheel  of  most  tractor  engines  of  the  multiple 
cylinder  form  is  usually  marked  with  letters  which 
indicate  the  points  where  the  valves  open  and  close. 
The  crankshaft  should  be  turned  by  the  starting  crank, 
and  when  the  point  on  the  flywheel  that  indicates 
valve  opening  is  in  line  with  the  trammel  or  indicator 
that  usually  indicates  the  vertical  center  line  of  the 
engine,  there  should  be  no  clearance  between  the  valve 
stem  and  the  plunger  that  operates  it.  When  the 
other  valve  is  open  in  the  same  cylinder,  then  there 
should  be  an  appreciable  clearance  between  the  valve 
plunger  and  end  of  valve  stem.  This  is  given  as  0.007" 
for  the  inlet  valves  and  0.01"  for  the  exhaust  valves. 
More  clearance  is  provided  between  the  exhaust  valve 


The  Modern  (Ias  Tractor  381 

stems  and  plungers  on  account  of  the  greater  expansion 
of  these  members  due  to  heat. 

If  the  engine  timing  has  been  disturbed,  as  is  often 
the  case  when  an  engine  is  dismantled,  care  should  be 
taken  to  replace  the  timing  gears  just  as  they  were  before 
the  engine  was  taken  apart.  This  is  usually  indicated 
by  marks  made  by  the  manufacturer  of  the  motor.  If 
no  marks  are  noticed,  then  the  tractioneer  should  be 
careful  to  make  some  for  himself  in  order  that  he  will 
be  sure  to  replace  the  timing  gears  correctly.  The 
best  way  to  do  this  is  to  bring  one  of  the  pistons,  pre- 
ferably that  in  the  front  cylinder,  to  the  top  center 
and  to  see  that  both  valves  in  that  cylinder  are  closed. 
One  tooth  on  the  crankshaft  gear  is  then  marked  with 
a  center  punch,  or  steel  letter  stamp  or  even  with  a 
cold  chisel,  if  neither  of  the  others  is  available.  The 
teeth  on  the  larger  gear  which  drives  the  camshaft  on 
either  side  of  the  marked  tooth  on  the  crankshaft  gear 
are  then  marked  for  future  identification  in  the  same 
manner. 

In  case  the  engine  timing  is  lost  and  the  gears  or 
flywheel  are  not  marked,  the  traction  engine  operator 
may  approximate  the  proper  timing  as  follows:  The 
piston  in  either  the  front  or  rear  cylinder  is  brought 
to  the  end  of  its  upward  stroke  and  the  camshaft  is 
rocked  in  such  a  manner  that  both  valves  are  closed. 
The  timing  gears  are  then  meshed  and  locked  into  place. 
The  engine  crankshaft  is  then  turned  about  half  a  revo- 
lution and  the  exhaust  valve  is  watched  to  see  if  it 
rises  from  its  seat.  If  it  rises  from  its  seat  when  the 
piston  is  about  three-quarters  of  the  way  down  on  its 
stroke,  the  engine  may  be  considered  timed  approxi- 
mately correct  and  if  nothing  else  has  been  disturbed, 
such  as  the  cams  on  the  shaft,   etc.,   the  rest  of  the 


382  The  Modern  Gas  Tractor 

cylinders  will  undoubtedly  be  timed  correctly  enough 
so  the  engine  will  start  without  difficulty.  If  the  exhaust 
valve  opens  late  the  timing  gear  may  be  moved  a  few 
teeth  and  again  meshed  with  the  gear  on  the  crank- 
shaft. The  crankshaft  is  rotated  again  and  the  opening 
of  the  exhaust  valve  again  noted.  The  closing  point 
is  next  determined  by  continuing  to  turn  the  crank- 
shaft. The  exhaust  valve  remains  open  during  the  next 
upstroke  of  the  piston  and  does  not  close  till  after  the 
piston  starts  on  the  intake  stroke.  Right  after  the 
exhaust  valve  closes,  the  intake  valve  should  open  and 
remain  open  during  the  next  down  stroke  of  the  piston, 
at  which  time  the  cylinder  should  fill  with  gas. 

To  facilitate  timing  it  may  be  well  to  mark  the  fly- 
wheel at  points  to  correspond  to  the  position  of  the  pis- 
ton in  the  first  cylinder  when  it  is  at  the  top  of  its  stroke 
and  similarly  when  it  is  at  the  bottom  of  the  cylinder. 
These  marks  may  be  made  with  a  center  punch  or 
steel  stamp  and  should  come  directly  opposite  each 
other.  They  are  of  greatest  value  on  engines  with 
inclosed  crankcase,  as  when  the  crankshaft  is  exposed, 
it  is  easy  to  follow  piston  movements  by  the  position 
of  the  crankpin  and  connecting  rod.  The  exhaust 
valve  generally  opens  about  30  degrees  crankpin  travel 
ahead  of  the  mark  corresponding  to  the  bottom  posi- 
tion of  the  piston  on  the  down  stroke  following  ignition. 
The  valve  remains  open  the  remainder  of  that  stroke 
and  the  entire  next  stroke,  closing  a  few  degrees  after 
the  piston  has  started,  on  the  suction  stroke.  The 
inlet  valve  opens  about  15  degrees  late  and  closes  about 
10  degrees  late.  The  exhaust  valve  thus  remains  open 
a  period  equal  to  about  220  degrees  crankshaft  travel, 
the  inlet  valve  seldom  remaining  open  more  than  180 
degrees.    The  ignition  spark,  with  timing  lever  at  center 


The  Modern  Gas  Tractor  383 

position  on  quadrant,  should  take  place  just  when  the 
piston  reaches  the  end  of  the  compression  stroke. 

Care  of  Piston  and  Rings. — Very  often  poor  com- 
pression is  caused  by  a  defective  condition  of  the  piston 
or  piston  rings.     If  lubrication  has  been  neglected  and 
the  cylinder  has  seized  at  any  time,  both  the  piston 
and  cylinder  walls  will  be  found  scratched  and  scored. 
Even  if  lubrication  has  not  been  neglected,  but  poor 
oil  or  an  insufficient  quantity  has  been  used,  the  same 
scratches  will   be   apparent   though   not   to  so  large   a 
degree.     The  piston  rings  may  break,  which  will  allow 
the   gas   to   escape   through   the   division   between   the 
broken   parts.      They    may   become   gummed   in   their 
grooves  so  they  do  not  spring  out  as  they  should  and 
gas   can   blow   by   them.      In   cases   where   the   piston 
rings  are  not  pinned  the  slots  in  the  rings  may  work  in  line 
and  permit  gas  to  escape  through  the  series  of  openings. 
Piston  rings  often  lose  their  elasticity  or  spring,  or 
they  may  wear  to  such  an  extent  that  they  will  not 
form  an  effective  seal  against  the  explosive  pressure. 
In  event  of  deterioration,  the  only  method  is  to  replace 
the  rings  with  new  members.     If  the  piston  rings  do 
not  work  freely  in  the  grooves,  they  should  be  removed 
from  the  piston  and  all  burnt  oil  cleaned  off.     The  car- 
bon deposits  which  have  collected  in  the  grooves  should 
also    be    removed    before    the    rings    are    replaced.     If 
the  piston  and  cylinder  walls  are  badly  scored  the  only 
remedy  is  to  have  the  cylinder  bore  ground  out  to  a 
new  surface  and  use  a  new  piston  member  made  to 
fit  the  enlarged  bore.     This  will  mean  that  new  rings 
must  be  fitted  as  well  as  a  new  piston.     Many  believe 
that  the  cheapest  way  in  the  end  is  to  secure  an  entirely 
new  piston  and  cylinder  from  the  makers  to  replace  the 
defective  members. 


384  The  Modern  Gas  Tractor 

Noisy  Operation. — A  number  of  power  plant  de- 
rangements are  readily  noted  because  they  give  positive 
indication  of  trouble  by  noises  easily  distinguishable 
by  the  untrained  ear.  Knocking  or  rattling  sounds 
are  usually  the  result  of  wear  in  the  connecting  rods 
or  main  bearings,  though  often  a  very  sharp  knock, 
such  as  might  be  attributed  to  a  loose  bearing,  is  due 
to  carbon  deposits  in  the  cylinder  or  combustion  chamber, 
premature  ignition  due  to  advance  spark  lever  or  a 
loose  flywheel.  Dry  bearings  are  invariably  indicated 
by  squeaking  sounds  and  whenever  this  signal  of  dis- 
tress is  heard  the  engine  should  be  stopped  immediately 
and  oil  applied  to  the  parts  which  have  indicated  their 
dry   condition. 

Leaks  produce  whistling  or  blowing  sounds;  a  sharp, 
definite  pitched  whistle  denotes  the  escape  of  gas  under 
pressure  and  is  usually  produced  by  a  defective  pack- 
ing or  gasket  that  is  used  between  the  cylinder  and 
cylinder  head  or  as  a  joint  for  the  exhaust  manifold. 
A  blowing  sound  is  caused  by  leaky  packing  in  the 
crank  case,  worn  main  bearings  or  wear  in  the  valve 
plunger  guides.  Grinding  noises  in  the  motor  are  usually 
caused  by  the  timing  gears  and  will  be  heard  if  these 
gears  are  dry  or  if  they  have  become  worn.  Minor 
rattles  often  indicate  nothing  more  serious  than  too 
great  clearance  between  valve  stem  and  their  operating 
plungers,  or  wear  in  the  valve  plunger  guides.  Any 
loose  driving  connection  anywhere  on  the  engine  will 
contribute  its  quota  of  noise  and  often  a  combination 
of  sounds  are  produced  that  will  be  very  annoying  even 
if  they  do  not  indicate  serious  wear. 

Adjusting  Bearings. — The  most  fertile  source  of 
noisy  operation  is  wear  in  the  main  bearings  of  the 
engine    or    looseness    in    the    connecting    rod    bearings. 


The  Modern  (Jas  Tkactor 


385 


The  points  where  deterioration  produces  the  most  noise 
are  clearly  indicated  at  Fig;.  163,  which  shows  the  bottom 
view  of  the  top  half  of  a  four-cylinder  engine  crankcase. 
This  shows  clearly  the  five  main  bearings  of  the  crank- 
shaft, two  of  these  members,  that  on  the  rear  and  the 
one  next  to  it,  having  the  bearing  cap  removed  in 
order  to  show  the  shaft  journals.  Under  the  influence 
of  the  explosions  the  bearings  in  time  tend  to  become 


CRANKSHAFT      UPPE R  HALF  CRANKCASE 


MAIN  BEARING  CAP 
BOLTS 


AIN  BCARING  CAP 


Fig.  163. — Bottom    View    of    Crankcase    With    Bottom    Half 
Removed  to  Expose  Crankshaft  and  Main  Bearings. 

hammered  down  a  trifle  and  lost  motion  exists  between 
the  crankshaft   and  the  bearing  bushes. 

If  the  wear  is  comparatively  slight  it  may  be  eliminated 
by  removing  some  of  the  thin  shims  of  sheet  metal 
placed  between  the  bearing  caps  and  the  lower  portion 
of  the  box  and  replacing  the  caps.     This  will  enable 


380  The  Modern  Gas  Tractor 

them  to  bed  down  closer  to  the  crankshaft  and  the  lost 
motion  which  produces  the  noise  will  not  exist.  If  the 
bearings  have  worn  to  such  an  extent  that  removing 
the  shims  will  not  be  sufficient,  new  brasses  or  bushings 
must  be  inserted  in  the  boxes  and  scraped  to  fit  the 
crankshaft.  If  the  crankshaft  is  cut  or  scored,  the 
journals  should  be  smoothed  with  fine  emery  cloth 
before  attempt  is  made  to  fit  the  bearings  to  the  shaft. 
A  typical  connecting  rod  in  a  disassembled  condition 
is  shown  at  Fig.   164  with  the  various  parts  separated 


CONNECTING  ROD  CAP  BOLTS 


^CONNECTING  ROD 
CAP 


WRISTP1N  BUSHING  CONNECTING  ROD  BUSHING5 


Fig.  164. — Connecting  Rod  of  Gas  Tractor  Power  Plant  Show- 
ing Removable  Crankpin  Brasses. 

in  order  that  the  construction  may  be  clearly  ascer- 
tained. It  will  be  noticed  that  the  small  bushing  which 
surrounds  the  wrist  pin  is  a  solid  member  pressed  into 
the  boss  at  the  upper  end  of  the  connecting  rod.  If 
any  wear  exists  at  this  point  the  old  bushing  should 
be  forced  out  and  replaced  by  a  new  member.  The 
lower  portion  of  the  connecting  rod  which  encircles 
the  crank  pin  is  provided  with  a  split  box  composed 
of  two  white  metal  bushings  that  bed   into  the  con_ 


The  Modern  Gas  Tractor 


387 


necting  rod  and  the  connecting  rod  cap,  respectively. 
The  two  halves  of  the  connecting  rod  lower  end  are 
usually  separated  by  thin  shims  or  liners,  such  as  used 
in  main  bearings,  and  if  the  connecting  rod  is  not  very 
loose,  lost  motion  may  be  e  iminated  by  removing  enough 
of  the  thin  shims  and  then  joining  the  parts  together  se- 
curely. If  the  connecting  rod  bushings  are  worn  too  much 
to  permit  refitting,  they  can  be  easily  replaced  by  new 
members  secured  from  the  maker. 

The  average  tractor  operator  is  not  apt  to  be  a  good 
enough  mechanic  to  scrape  in  and  refit  a  set  of  main 
bearings,  but  this  process  is  not  a  difficult  one  to  learn, 
the  only  requirements   being  that  the  workman   shall 


Fig.  165.— Tools    That    Facilitate    Refitting    of    Bearings. 

be  reasonably  careful,  have  the  proper  tools  and  be 
patient  enough  to  fit  the  bearings  properly  The  tools 
shown  at  Fig.  165  will  considerably  facilitate  refitting 
of  bearings.  The  set  of  three  scrapers  shown  will  prove 
adequate  for  all  sizes  of  bushings  while  the  socket 
wrench  set  will  make  the  constant  removal  and  replace- 
ment of  the  bearing  cap  nuts  a  less  difficult  task  than 
if  the  ordinary  form  of  monkey  wrench  is  used.  When 
refitting  the  main  bearings  the  first  precaution  is  to 
clean  the  crankshaft  thoroughly.  Only  attempt  to 
fit  one  box  at  a  time,  as  if  more  than  one  bearing  cap 
is  tightened  it  will   be  hard  to  tell   which   one   is   too 


388  The  Modern  Gas  Tractor 

tight.  After  the  shaft  and  boxes  have  been  cleaned, 
the  main  journals  of  the  crankshaft  should  be  coated 
with  a  very  light,  thin  film  of  Prussian  blue  pigment 
which  may  be  obtained  in  a  collapsible  tube  at  any 
paint  store.  The  crankshaft  is  then  dropped  in  the  boxes 
which  are  held  by  the  engine  base  and  revolved  a  number 
of  times  in  order  that  all  the  high  spots  on  the  boxes 
will  have  a  chance  to  run  against  the  shaft.  When 
the  shaft  is  removed  the  high  spots  will  be  indicated 
by  specks  of  blue  on  the  brasses. 

Before  again  replacing  the  crankshaft,  these  high 
spots  are  scraped  off  by  means  of  curved  bearing  scrapers. 
The  shaft  is  again  replaced  and  revolved  so  that  it 
will  indicate  another  set  of  high  places.  The  scraping 
in  process  is  continued  on  all  of  the  lower  boxes  until 
the  crankshaft  has  many  points  of  bearings  evenly  dis- 
tributed at  each  box.  The  caps  are  the  next  to  receive 
attention.  The  shaft  is  allowed  to  remain  in  place  and 
one  cap  is  fitted  at  a  time.  The  crankshaft  journals 
are  kept  covered  with  Prussian  blue,  a  new  film  being 
put  on  with  the  finger  each  time  a  test  for  high  places 
is  to  be  made.  The  fitting  is  started  with  either  the 
front  or  rear  main  bearing  cap  which  is  brought  against 
the  shaft  by  means  of  the  retaining  nuts,  until  it  is 
difficult  to  turn  the  shaft.  The  nuts  are  slacked  up 
a  trifle  and  the  crankshaft  turned.  Part  of  the  Prus- 
sian blue  will  be  scraped  off  by  the  high  points  in  the 
bearing  caps  and  these  are  removed  by  the  scraper 
and  the  fitting  process  continued  until  the  bearing 
cap  shows  an  equal  bearing  by  a  uniform  distribution 
of  color.  The  cap  is  properly  fitted  when  the  crank- 
shaft does  not  turn  unduly  hard  with  the  bearing  cap 
retaining  nuts  bedded  down  firmly  and  the  cap  in 
firm   contact  with   the   engine  base   or  the  interposed 


Tn io  Modern  Gas  Tractor  389 

shims  of  metal.  Each  cap  is  fitted  in  turn,  and  if  the 
work  is  carefully  done  it  will  be  found  possible  to  turn 
the  crankshaft  over  without  much  difficulty  when  all 
the  caps  have  been  properly  replaced  and  no  lost  motion 
will  exist  between  the  caps  and  crankshaft. 

The  same  instructions  apply  to  fitting  connecting 
rods,  the  test  for  high  spots  being  made  by  the  use  of 
Prussian  blue  pigment  and  the  trial  to  ascertain  if  the 
bearing  clamps  the  shaft  too  tightly  is  made  by  rocking 
the  connecting  rods  back  and  forth.  The  degree  of 
resistance  indicates  the  fit  of  the  bearing.  A  con- 
necting rod  is  usually  considered  properly  fitted  if  it 
is  not  loose  and  yet  will  drop  over  slowly  due  to  the  piston 
weight  when  placed  in  a  vertical  position.  Care  should 
be  taken  not  to  adjust  bearings  too  tightly,  as  this  may 
produce  sufficient  heating  to  burn  out  the  white  metal 
bushings  or  score  the  crankshaft  journals  badly  when 
harder  materials,  such  as  bronze,  are  used.  Before 
replacing  either  connecting  rod  or  main  bearing  caps 
for  the  last  time,  it  will  be  well  to  use  liberal  quantities 
of  cylinder  oil  to  insure  that  they  will  be  properly 
lubricated  when  the  power  plant  is  first  started  after 
the  refitting  process   is   complete. 

Mixture  Troubles. — Defective  carburetion  is  usu- 
ally indicated  by  misfiring  or  irregular  operation.  The 
common  derangements  of  the  components  of  the  fuel 
system  and  the  best  method  for  their  location  follow: 
The  first  thing  to  do  is  to  see  if  the  fuel  is  flowing  to 
the  carburetor  from  the  tank.  This  is  done  by  dis- 
connecting the  feed  pipe  and  seeing  if  the  stream  coming- 
out  is  the  full  size  of  the  orifice.  If  it  trickles  out  slowly 
it  is  an  indication  that  either  the  pipe  is  clogged  with 
dirt  or  that  there  is  an  accumulation  of  scale,  rust  or 
lint  at  the  strainer  screen  usually  placed  in  tank  over 


390  The  Modern  Gas  Tractor 

the  gasoline  discharge  coupling.  This  may  also  indicate 
that  there  is  not  enough  liquid  in  the  tank.  Insufficient 
fuel  supply  is  sometimes  due  to  the  shutoff  valve  between 
the  tank  and  carburetor  having  jarred  either  partly 
or  wholly  closed  because  of  vibration.  If  the  stream 
of  fuel  from  the  tank  indicates  that  it  is  reaching  the 
carburetor  all  right,  that  device  should  be  examined 
to  see  if  there  is  any  dirt  or  water  in  the  float  chamber. 
The  float  chamber  of  most  carburetors  may  be  drained 
by  a  petcock  provided  for  the  purpose.  Dirt  may 
constrict  the  passage  between  the  flow  chamber  and 
the  spray  nozzle  and  very  often  the  fine  holes  or  spray 
openings  in  the  latter  may  become  blocked  up  by  par- 
ticles of  foreign  matter.  The  float  may  be  binding  and 
the  gasoline  needle  valve  regulating  the  supply  opening 
in  the  bowl  may  stick  to  its  seat.  Any  of  these  condi- 
tions would  reduce  the  supply  of  fuel  and  the  engine 
would  not  receive  sufficient  quantities  of  properly  pro- 
portioned gas. 

Some  of  the  conditions  that  will  produce  poor  mixture 
are:  The  air  valve  spring  may  be  weak  or  broken, 
the  gasoline  or  fuel  adjusting  needle  may  be  loose  and 
jar  out  of  adjustment,  the  air  valve  spring  adjusting 
nuts  may  be  a  poor  fit  on  the  valve  stem  and  adjust- 
ments will  not  be  retained,  air  may  leak  in  through 
leaky  joints  of  the  inlet  manifold  or  through  holes  of 
a  porous  casting;  or  the  valve  stem  may  have  worn 
enough  in  the  guides  so  air  is  drawn  into  the  mixture 
through  the  worn  inlet  valve  stem  guide  bushings.  Any 
foreign  matter  in  the  fuel  will  cause  irregular  operation 
because  the  standpipe  bore  may  be  partially  constricted 
and  not  allow  enough  fuel  to  reach  the  mixture. 

If  clouds  of  black  smoke  are  expelled  from  the  exhaust 
pipe  it  indicates  that  the  fuel  supplied  the  mixture  is 


The  Modern  Gas  Tractor  391 

excessive  and  the  supply  should  be  reduced  by  screwing 
down  on  the  needle  valve  in  carburetors  where  this 
method  of  regulation  is  provided.  If  no  needle  valve  is 
used  the  fuel  proportions  may  be  reduced  by  altering  the 
fuel  level  in  the  float  bowl.  A  pronounced  "popping" 
in  the  carburetor  means  that  the  mixture  contains  too 
much  air.  If  this  is  not  due  to  air  leaking  in  through 
worn  valve  guides  or  leaky  manifolds  it  may  be  over- 
come by  screwing  in  the  auxiliary  air  valve  adjustment 
so  the  valve  does  not  open  so  much  or  by  slightly  in- 
creasing the  fuel  supply  by  opening  up  the  regulating 
needle.  The  exhaust  gas  will  be  free  from  any  objec- 
tionable odor  and  will  be  clean  if  fuel  is  not  burnt  in 
excess.  The  character  of  the  mixture  may  be  judged 
by  the  color  of  the  flame  issuing  from  the  exhaust  pipe 
if  the  engine  is  run  with  an  open  throttle  after  dark. 
A  red  flame  indicates  too  much  gasoline,  and  a  yellowish 
one  shows  an  excess  of  air.  A  pronounced  blue  flame 
such  as  given  by  a  gas  stove  or  gasoline  stove  burner 
will  indicate  the  properly  proportioned  mixture. 

Ignition  System  Derangements. — When  a  battery 
ignition  system  is  provided  and  the  engine  does  not 
run  regularly  the  first  thing  to  look  for  is  to  see  if  there 
is  a  spark  at  the  spark  plugs.  These  members  are  re- 
moved from  the  cylinders  and  are  then  again  coupled 
up  to  the  secondary  wires.  They  are  laid  on  the  cylinder 
castings  in  such  a  way  that  the  bushing  intended  to 
be  screwed  into  the  cylinder  is  in  good  metallic  contact 
but  the  insulated  terminal  at  the  upper  end  out  of 
contact.  The  engine  is  then  turned  over  slowly  by 
hand  and  the  spark  plugs  watched  to  see  if  there  is 
any  spark  between  the  points.  If  there  is  no  indication 
of  current  flow  the  following  may  be  looked  for:  A 
broken  wire  anywhere  in  the  primary  circuit,  a  defective 


392 


Tin:  Modern  Gas  Tractor 


ground  connection,  loose  battery  terminals,  broken 
battery  connections,  lack  of  current  at  the  battery. 
The  method  of  testing  dry  cells  is  extremely  simple 
and  is  outlined  at  Fig.  166.  Each  cell  is  tested  in  turn 
by  a  small  watch  size  testing  instrument  which  indicates 
the  available  current  strength  in  amperes.  Any  dry 
cells  that  read  below  six  or  seven  should  be  rejected 
and,  in  fact,  it  will  be  well  to  replace  dry  cells  unless 
they  indicate  at  least  eight  amperes. 


Fig.  166.— Method  of  Testing  Capacity  of  Dry  Cell. 

If  there  is  no  spark  at  the  plugs  but  the  spark  coil 
vibrators  buzz  properly  this  shows  that  the  primary 
wiring  is  all  right  and  that  the  fault  must  be  looked  for 
either  in  the  wires  comprising  the  secondary  circuit 
or  at  the  spark  plugs  themselves.  Spark  plugs  may  be 
rendered  inoperative  by  cracked  insulation  or  by  deposits 


The  Modern  Gas  Tractor  398 

of  carbon  around  the  electrode.  Secondary  wires  some- 
times break  or  may  become  oil  soaked  or  have  the 
insulation  worn  away,  either  of  which  permits  the 
current  to  become  grounded  to  some  metal  part  of  the 
motor.  The  electrodes  of  a  spark  plug  may  have  burnt 
away  enough  so  the  gap  is  too  great  or  the  points  may 
be  too  close  together.  If  there  is  no  vibration  at  the 
spark  coil  the  trouble  may  be  due  to  broken  timer 
wires,  burnt  or  pitted  vibrator  contact  points,  vibrator 
out  of  adjustment,  or  poor  connections  at  the  com- 
mutator or  timer. 

If  a  low  tension  magneto  is  fitted  as  an  auxiliary 
supply  of  current,  about  the  only  thing  that  will  cause 
failure  of  current  generation  outside  of  slipping  or 
broken  driving  connections  is  brush  trouble.  The 
commutator  sometimes  becomes  covered  with  an  oil 
glaze  or  the  brush  holders  may  become  fouled  with 
old  oil.  Either  of  these  conditions  interferes  with  the 
flow  of  the  current.  The  brushes  may  become  worn 
so  they  no  longer  bear  on  the  commutator  and  the 
current  generated  by  the  armature  cannot  be  collected 
and  sent  to  the  outer  circuit.  Obviously  any  derange- 
ment of  the  driving  connections  will  interfere  with 
current  generation  because  the  armature  will  not  be 
turned  sufficiently  regular  or  at  the  proper  speed. 

If  a  high  tension  magneto  is  fitted  and  no  spark  is 
produced  at  the  plugs  the  following  defective  conditions 
should  be  looked  for:  Broken  secondary  wires,  current 
collecting  brushes  or  distributor  brush  not  making  con- 
tact, contact  points  of  the  make-and-break  device 
may  be  out  of  adjustment  or  covered  with  oil;  the 
wiring  may  be  attached  to  wrong  terminals;  the  dis- 
tributor filled  with  metallic  particles,  carbon  dust  or 
oil    accumulations;     the   distributor   contacts    may   not 


.">'.»4  The  Modern  Gas  Tractor 

be  making  proper  connections  because  of  wear  or  a 
defective  distributing  brush  or  more  serious  derange- 
ment may  exist,  such  as  defective  windings  or  conden- 
sers, which  fortunately  are  of  extremely  rare  occurrence. 

Cooling  and  Lubrication  Group  Faults. — Owing 
to  the  simplicity  of  the  cooling  systems  ordinarily  used 
on  gas  tractors  they  are  not  liable  to  give  trouble  if 
the  radiator  or  tank  is  kept  full  of  clean  water  and  the 
circulation  is  not  impeded.  The  most  common  troubles 
producing  defective  cooling  are  due  to  impeded  water 
circulation.  A  radiator  may  become  clogged  with  rust 
or  sediment  and  the  piping  or  water  jackets  some- 
times become  filled  with  scale  that  tends  to  retard  the 
flow  of  water.  If  the  water  pump  or  its  driving  means  fail, 
circulation  will  not  be  positive  and  overheating  will  re- 
sult, as  is  also  evident  if  the  cooling  fan  belt  breaks  or  slips. 

When  rubber  hose  is  used  in  the  circulation  system, 
this  may  deteriorate  inside  and  the  area  of  the  inside 
passages  become  reduced  due  to  particles  of  rubber 
hanging  down.  The  cooling  system  is  often  apt  to 
overheat  after  anti-freezing  solutions  of  which  calcium 
chloride  forms  a  part  have  been  used,  as  crystals  of  the 
salt  may  collect  in  the  radiator,  piping  or  water  jackets. 
These  crystals  can  only  be  dissolved  by  chemical  means 
when  in  inaccessible  places,  but  where  the  construction 
permits  they  may  be  removed  by  scraping.  Over- 
heating is  sometimes  caused  by  rich  mixture  and  some- 
times by  defective  lubrication. 

When  the  oiling  group  is  not  working  properly  the 
friction  between  the  parts  of  the  mechanism  usually 
produces  heat.  Poor  lubrication  usually  results  from: 
Not  enough  oil  in  the  engine  crank  case  or  mechanical 
oiler,  oil  of  poor  quality,  broken  or  clogged  oil  pipes, 
broken   oil   pump   or   defective   oil   pump   drive.      The 


The  Modern  Gas  Tractor 


395 


oil  supply  may  be  reduced  by  defective  inlet  or  discharge 
check  valves  at  a  mechanical  oiler  or  by  worn  pump- 
plungers  in  that  device.  A  clogged  oil  passage  or  pipe 
leading  to  an  important  bearing  point  will  result  in 
loss  of  power  and  overheating  because  the  oil  cannot 
get  between  the  working  surfaces.  Much  of  the  trouble 
caused  by  defective  oiling  may  be  prevented  by  using 
only  the  best  grades  of  lubricating  oil,  and  lubricants 


*•*'  _, 


VI 


JL    I 


23»  ■ 


Fig.  167. — Assembly  View  of  Reversing  Gear,  Main  Drive  and 
Differential  Gearing  of  "Twin  City  40"  Gas  Tractor. 

of  poor  quality  will  cause  friction  and  overheating  even 
if  all  parts  of  the  oil  system  are  working  properly. 
If  a  mechanical  oiler  becomes  inoperative  or  its  driving 
means  fail  while  the  tractor  is  in  the  field,  the  engine 
may  be  kept  in  operation  by  putting  enough  oil  in  the 


:>!M;  The  Modern  Gas  Tractor 

crank  case  so  the  connecting  rods  will  dip  into  it  as  the 
crank-shaft    revolves. 

Running  Gear  Derangements. — Running  gear 
trouble  and  its  cause  is  usually  apparent  as  soon  as  it 
happens.  If  a  clutch  refuses  to  hold  or  if  a  shifting 
gear  will  not  engage  it  is  obviously  due  to  some  mechani- 
cal derangement  that  can  be  fixed  as  soon  as  located. 
A  typical  transmission  system  is  shown  at  Fig.  167, 
and  in  this  various  driving  members  and  the  bearings 
as  well  as  clutch  and  gear  shifting  levers  are  clearly 
shown.  There  are  some  points  about  the  running  gear 
of  a  tractor  where  wear  or  loose  parts  may  directly 
concern  the  safety  of  the  driver.  A  defect  in  either 
the  steering  gear  or  the  brakes  might  result  disastrously 
to  the  operator  in  event  of  failure. 

One  of  the  most  important  members  of  the  transmis- 
sion system,  which  the  writer  will  consider  in  connection 
with  the  running  gear  assembly,  is  the  clutch,  and  de- 
rangements of  this  member  will  affect  the  efficiency 
of  the  entire  assembly.  The  most  common  defects  are 
failure  to  engage  properly,  slipping  under  load  and 
"grabbing,"  which  is  the  result  of  too  sudden  engage- 
ment. The  former  condition  is  usually  the  result  of 
wear  of  the  wood  friction  blocks,  and  may  generally  be 
easily  compensated  for  by  screwing  out  on  the  adjust- 
ment provided  so  the  clutch  blocks  may  be  brought 
more  forcibly  into  contact  with  the  clutch-ring  when  the 
actuating  lever  is  operated.  Slipping  may  be  caused  by 
charred  or  broomed  out  friction  blocks,  and  when  this 
condition  is  evident  the  best  remedy  is  to  replace  these 
members. 

If  the  clutch  engages  too  suddenly  it  is  generally  due 
to  the  adjustment  having  been  taken  up  to  a  point 
where  the  hand  lever  need  only  be  moved  a  very  small 


The  Modern  Gas  Tractor  :\{.)7 

amount  to  produce  clutch  engagement.  This  can 
be  prevented  by  proper  attention  to  the  clutch  adjust- 
ments. If  a  clutch  shifting  collar  is  worn  too  much,  or 
the  small  pins  in  the  yokes  of  the  rods  connecting  the 
clutch  operating  bell  crank  with  the  hand  lever  are 
worn,  it  may  take  too  much  movement  of  the  handle 
to  set  the  clutch.  This  defect  can  be  easily  remedied 
by  replacing  the  worn  members. 

Not  much  trouble  is  produced  by  the  gearing  of  a 
tractor  until  the  gear  teeth  become  worn.  When  shift- 
ing members  are  used  to  obtain  changes  of  speed  there 
may  be  some  difficulty  met  with  in  sliding  these  into 
mesh  if  the  edges  of  the  teeth  are  burred  over,  and  this 
often  causes  trouble  on  the  teeth  of  the  positive  jaw 
clutches  used  in  connection  with  reversing  gears.  Diffi- 
culty in  clutch  or  gear  shifting  is  sometimes  due  to 
binding  of  the  control  levers  or  operating  rods  because 
of  accumulations  of  rust  or  dirt.  Driving  gears  do  not 
give  much  trouble,  though  when  the  teeth  become  worn 
or  the  bearings  in  which  the  shafts  run  become  loose, 
there  will  be  considerable  noise  and  rattle  while  the 
gearing  is  in  action. 

Where  chains  are  used  for  driving,  these  for  the  most 
part  are  run  without  covering  of  any  kind,  and  as  the 
action  of  the  dirt  and  gravel  is  to  combine  with  the 
grease  on  the  outside  and  form  an  abrasive,  consider- 
able wear  will  result  if  the  chains  are  not  kept  clean. 
To  obtain  proper  results  from  driving  chains,  they  must 
be  kept  in  proper  adjustment.  A  chain  that  runs  too 
loose  is  apt  to  climb  the  teeth  of  a  sprocket,  whereas 
if  it  is  adjusted  too  tightly  they  are  liable  to  break, 
especially  if  the  sprocket  teeth   are  worn   hook    shape 

Not  much  trouble  is  caused  by  bearings  if  these  are 
kept  properly  oiled.     The  same  rules  previously  giver 


398 


The  Modern  Gas  Tractor 


for  fitting  engine  bearings  apply  just  as  well  to  the 
plain  bearings  used  for  supporting  the  differential 
cross  shaft  or  the  rear  axle.  In  some  tractors  anti- 
friction bearings  are  used,  these  being  of  the  ball  or  roller 
type.  It  is  important  that  the  oil  used  with  bearings 
of  this  nature  contains  no  acid,  and  care  should  be 
taken  to  prevent  dirt  or  grit  from  entering  the  bearing 
housings. 


Fig.  168. — Driving  Gears  of  "Twin  City  25"  Gas  Tractor. 

Grinding  sounds  in  gearing  are  usually  produced  by 
gears  meshing  too  deeply,  while  worn  gears  usually 
manifest  their  defective  condition  by  rattling.  The 
wheels  should  be  tested  from  time  to  time  to  see  that 
their  bearings  are  not  worn  unduly  by  jacking  up  the 
tractor  frame  and  turning  or  shaking  them  after  they 


Thk  Modern  Gas  Tractor  :!'.>!» 

are  relieved  of  the  machine's  weight.  With  a  one  piece 
front  axle  the  important  point  to  watch  is  the  sup- 
porting pivot,  and  this  should  be  kept  clean  and  well 
oiled  at  all  times.  Steering  chains  should  be  examined 
frequently  to  make  sure  that  no  links  have  started 
to  pull  apart  and  that  they  are  in  proper  condition. 
When  an  Ackerman  type  axle  is  used,  the  steering 
knuckles  should  be  looked  over  to  make  sure  that  the 
spindle  bolts  are  right  and  at  the  same  time  the  various 
joints  of  the  drag  link  and  tiebar  should  be  carefully 
examined  for  any  lost  motion.  It  will  be  well  to  encase 
all  of  the  joints  of  a  steering  system  in  small  leather 
bags  packed  with  grease,  because  if  these  are  kept 
well  lubricated  and  protected  from  grit,  very  little  wear 
will   exist   at   these   points. 

The  brake  should  be  always  kept  in  proper  adjust- 
ment. The  means  prov  ded  are  available  on  inspection. 
If  the  brake  fails  to  hold  properly  the  friction  facing 
should  be  examined  to  see  that  it  has  not  become  worn 
and  the  various  portions  of  the  operating  levers  should 
be  inspected  to  see  that  there  are  no  weak  points  or 
worn  parts  liable  to  give  out  at  a  critical  time.  A 
brake  should  not  be  adjusted  too  tightly,  because  if 
it  bears  on  the  brake  drum  when  in  released  position 
it  will  cause  friction  and  produce  loss  of  power.  At 
the  other  hand  if  the  brake  is  not  adjusted  sufficiently 
tight  a  full  movement  of  the  operating  lever  will  not 
apply  the  brake  tight  enough  to  stop  the  tractor. 

An  important  point  to  observe  when  the  wheels  are 
of  the  built-up  construction  is  that  the  spokes  are 
kept  properly  tightened,  as  one  or  more  loose  spokes 
in  a  wheel  will  seriously  reduce  the  strength  of  the 
assembly.  A  typical  built-up  wheel,  in  which  the  spokes 
are  screwed  into  the  cast  hub  and  held  in  place  by 


400 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor  401 

lock  nuts,  is  shown  at  Fig.  168,  and  to  tighten  these 
members  the  lock  nuts  must  be  slacked  up  and  the 
threaded  end  of  the  spoke  screwed  into  the  hub  more 
tightly  with  a  Stilson  or  pipe  wrench,  then  locked  in 
place  with  the  lock  nut. 

Tractor  Hitches. — The  use  to  which  the  gas  tractor 
has  been  more  widely  applied  than  any  other  is  in 
furnishing  power  for  pulling  ploughs.  The  hitch  required 
is  relatively  simple,  as  the  gang  of  from  six  to  twelve 
ploughshares  is  attached  to  the  tractor  drawbar  as  a 
compact  unit.  The  only  precaution  to  observe  is  that 
the  chains  by  which  the  plough  is  pulled  should  be  at- 
tached to  the  drawbar  in  such  a  way  that  an  even 
draft  will  be  obtained  and  the  ploughs  trail  along  directly 
back  of  the  tractor.  If  a  large  number  of  bottoms  are 
provided  and  the  total  width  of  the  gang  exceeds  that 
of  the  tractor,  the  plough  frame  must  be  attached  to 
the  drawbar  so  that  the  ploughshare  that  is  in  the  furrow 
last  cut  will  be  about  on  a  line  with  the  high  tractor 
driving  wheel  outer  edge.  Under  these  conditions  it 
is  not  possible  to  have  the  plough  pull  as  evenly  as  when 
a  lesser  number  of  shares  are  used,  because  those  which 
project  beyond  the  tractor  cannot  fail  to  produce  a 
side  draft. 

Two  common  forms  of  the  gang  plough  have  been 
devised  for  use  with  the  gas  tractor.  That  at  Fig.  172 
shows  a  conventional  five  bottom  gang  with  hand  op- 
erated levers  to  control  the  depth  of  cut  and  the  action 
of  the  ploughshares.  Most  power  ploughs  are  provided 
with  a  wheel  or  colter  which  is  placed  just  in  advance 
of  the  plough  point  so  it  will  be  raised  automatically 
over  a  stone  or  other  impediment  that  might  damage 
the  plough.  A  platform  of  planks  is  placed  over  the 
forward  portions  of  the  frame  so  that  a  man  can  stand 


402 


The  Modern  Gas  Tractor 


The  Modern  Gas  Tractor 


403 


on  the  plough  and  control  the  levers  as  desired.  As 
this  means  that  two  men  must  be  employed  in  plough- 
ing, another  form  of  gang  plough  which  is  known  as 
the  "self-lift"  has  been  devised  to  make  it  possible  for 
the  engineer  of  the  tractor  to  control  the  ploughs  directly 
from  his  position  on  the  tractor  platform. 


Fig.  171. — Holt  Caterpillar  Tractor  at  Work  Ploughing  Deep 
Furrows. 

The  Avery  "self-lift"  engine  gang  plough,  having 
ten  ploughshares,  is  shown  at  Fig.  173.  At  Fig.  174 
the  method  of  raising  the  ploughshares  is  clearly  outlined. 
A  special  broad  tread  wheel  having  grouters  to  insure 


404 


The  Modern  Gas  Tractor 


Fig.  172.— Typical    Hand    Lift    Five    Bottom    Gang    Plough 
Adapted  for  Use  With  Traction  Engine. 


Fig.  173.— Avery  "Self  Lift"  Ten  Bottom  Gang  Plough  Makes 
It  Possible  for  Engineers  to  Control  Ploughs  Without 
Leaving  Tractor  Cab. 


The  Modern  Gas  Tractor 


405 


positive  drive  is  mounted  beneath  the  plough  frame  and 
drives  a  cross  shaft  by  means  of  chain  and  sprocket 
connection.  A  series  of  pivoted  bellcrank  arms  to 
which  the  ploughshare  beams  are  attached  by  chains 
are  utilized  in  lifting  them.  The  method  of  operation 
is  simple.  A  trip  lever  is  pulled  in  such  a  way  that  a 
clutch  is  engaged.  This  connects  the  driving  sprocket 
to  the  short  shaft  on  which  the  bevel  pinion  is  mounted 
that  meshes  with  the  bevel  gear  driving  the  eccentric 


Fig.  174. — View    Showing    Mechanism    of    Avery    "Self    Lift" 

Plough. 

shaft.  As  the  gears  turn,  the  eccentrics  pass  under 
the  rollers  in  the  plough  lifting  cranks,  and  in  this  man- 
ner the  ploughs  are  lifted  directly  by  means  of  power 
instead  of  by  the  usual  hand  lever. 

Many  traction  engine  operators,  especially  those  who 
have  to  cultivate  large  areas,  arrange  to  draw  a  number 
of  machines  at  the  same  time  and  thus  perform  different 
operations  on  a  certain  strip  of  ground  by  going  over 


400 


The  Modern  Gas  Tractor 


rv  "c  is  v  kvvvvui'dii  uvu  u 
l       PACKER        i 


3-3 


EIGHT  BOTTOM 
PLOW 


^ 


U        u      u       u 


TOOTH     HARROWS 


TOOTH   HARROWS 


Fig.  175. — Plan  Views  of  Combination  Hitches  That  Save 
Time  and  Labor.  A — Plough,  Packer  and  Toothed  Harrow. 
B — Plough,  Packer,  Drill  and  Toothed  Harrows. 


The  Modern  Gas  Tractor 


407 


2      M 

■5  V 

S   o 


n  S 


"S  H 


a  a 


a  _a 
=  H 


•a   ° 

-2    si 


T3  a 


.9  Pu 
h  — 

—       CO 

—  '5 

I—       Ih 

.    3 
(fife 


-      3 

a"      !S 

.Eh 


a  : 

.2  o 


go 


40S 


The  Modern  (Ias  Tractor 


it  only  once.  At  Fig.  175-A  a  hitch  is  shown  in  which 
an  eight  bottom  gang  plough  is  attached  directly  to 
the  tractor  drawbar.  A  packer  is  attached  to  the 
plough  and  tooth  harrows  are  drawn  in  turn  from  the 
packer.  By  utilizing  machines  in  this  manner  the 
ground  is  broken,  packed,  and  harrowed  at  one  time. 
Another  hitch  which  is  very  similar  is  shown  at  B. 
In  this  a  drill  is  interposed  between  the  packer  and  the 
tooth    harrows   and    thus  a  strip    of    ground    may    be 


Fig.  177. — Outfit  of  Berland  and  Lee,  Brady,  Mont.,  Ploughing 
With    Disc    Plough   and   Packing   With   Stone    Drag. 

ploughed,  packed,  seeded,  and  harrowed  in  practically 
one  operation.  The  illustration  at  Fig.  176  shows  a 
practical  application  of  a  plough,  packer,  tooth  harrow, 
and  drill,  actually  in  use  in  the  field.  That  at  Fig.  177 
clearly  demonstrates  the  utility  of  a  disc  harrow  or 
plough  and  stone  drag  packer  combination. 

The  number  of  auxiliary  machines  that  can  be  used 
in  connection  with  the  plough  depends  largely  upon 
the  power  of  the  tractor  available.     Some  of  these  have 


The  Modern  Gas  Tractor 


409 


wMmmww 


Fig.  178.— Simple   Three    Drill    Hitch    Easily    Made   by    Any 

Farmer. 


i  = 


fc  r .  o  i  n  c^?a  a  ^  e *p  1 


Fig.  179.— Wrought    Iron    Pipe    Drill    Hitch   for   Three    Drills. 


410 


The  .Modern  Gas  Tractor 


^~Vjfc 


Fig.  180. — Practical  Application   of   Drill   Hitch. 

just  barely  enough  to  haul  a  six  or  eight  bottom  gang 
plough  without  increasing  the  load  by  adding  other 
machines.  If  the  tractor  has  a  wide  margin  of  power 
it  is,  of  course,  possible  to  operate  other  farm  imple- 


Fig.  181. — Hansmann  Patent  Five  Drill  Hitch  Very  Useful 
in  Seeding  Large  Areas  as  It  Covers  a  Strip  Sixty  Feet 
Wide. 


The  Modern  Gas  Tractor 


411 


ments  without  straining  the  tractor.  The  ordinary 
eight-foot  disc  harrow,  which  weighs  about  six  hundred 
pounds,  requires  four  horses  to  draw  it.  This  means 
that  it  will  take  approximately  600  pounds  pull  for  a 
tractor  to  draw  it.  A  twenty-foot  drag  harrow  requires 
the  same  power  as  an  eight-foot  disc  harrow  and  the 
same  pull  will  also  operate  a  ten-foot  wide  clod  crusher. 
As  three  horses  will   usually  handle  a  twelve-foot  disc 


Fig.  182.— Avery  Gas  Tractor  Outfit  Owned  by  D.  M.  Circle, 
Kiowa,  Kansas,  Pulling  a  Double  Disc  and  Lever  Tooth 
Harrow. 

drill,  which  seeds  a  strip  eight  feet  wide,  a  pull  of  450 
pounds  will  be  needed  for  each  drill  hauled. 

An  easily  made  and  simple  drill  hitch  is  outlined  at 
Fig.  178.  The  method  of  attaching  the  drill  is  so  clearly 
shown  that  further  comment  is  not  necessary.  The 
ingenious  farmer  is  often  able  to  make  hitches  for  use 
in  connection  with  a  gas  tractor  by  utilizing  odds  and 
ends  that  are  found  on  any  farm  of  any  pretension?. 


412 


Tin:  Modern  Gas  Tractor 


i> 


,PCT»IL   OF    CLEVIS 


^P 


Fig.  183.— Details    of    Easily    Constructed    Harrow    Hitch    for 
Four  Ten  Foot  Disc  Harrows. 

At  Fig.  179  a  method  of  utilizing  wrought  iron  pipe 
and  fittings  so  that  three  12-foot  drills  will  obtain 
equal  draft  from  the  tractor  drawbar  is  outlined.  An 
old  wagon  axle  is  cut  in  half  and  one  wheel  is  attached 
at  each  end  of  the  long  four-inch  pipe  that  forms  the 
basis  of  the  attachment.  The  practical  application  of 
a  disc  and  drill  combination  is  shown  at  Fig.  180. 


Fiu.  1S4. — Practical  Application  of  1.  H.  C.  "Mogul"  Tractor 
in  Road  Grading  Work. 


The  Modern  Gas  Tractor  413 

When  one  considers  the  rapid  growth  of  the  gas  tractor 
industry  it  is  but  natural  to  assume  that  a  number 
of  attachments  would  be  devised  for  use  with  traction 
engines.  That  shown  at  Fig.  181  is  the  Hansmann 
five-drill  hitch,  which  makes  it  possible  for  a  tractor 
of  sufficient  power  to  pull  five  12-foot  drills  and  thus 
seed  a  strip  48  or  50  feet  wide.  An  easily  made  harrow 
hitch,  which  will  enable  the  tractor  to  pull  four  10-foot 
disc  harrows,  is  clearly  depicted  at  Fig.  183.     The  draft 


Pig.  185. — Avery  Gas  Tractor  Pulling  Western  Wagon  Loader 
and  Elevator  Grader. 

bar  of  this  device  is  composed  of  a  length  of  3"  x  6" 
beam  about  18  feet  long.  Four  clevises  are  spaced 
along  this  evener  bar.  The  bar  is  hauled  by  two  5-8" 
steel  cables,  secured  to  a  ring  at  one  end  and  to  clevises 
attached  to  the  beam  at  the  others.  The  ring  is  at- 
tached to  the  center  of  the  tractor  drawbar  or  in  the 
line  of  pull  if  the  harrows  are  drawn  by  a  gang  plough 
or    follow    any    other    implement.      The    details    of    the 


414  The  Modern  (J as  Tractor 

device  are  clearly  shown  and  should  be  easily  followed 
by  any  one  of  average  mechanical  ability. 

Utility  and  Uses  of  Modern  Gas  Tractors. — The 

gas  tractor  offers  many  advantages  in  road  construction 
and  they  are  rapidly  replacing  the  steam  tractors 
formerly  widely  employed  for  this  service.  A  con- 
vertible road  roller-tractor  combination  is  practically 
three  machines  in  one,  inasmuch  as  a  simple  change 
will  convert  the  tractor  to  a  road  roller  and  vice  versa 
and  the  machine  can  be  used  practically  all  the  year 
round,  as  it  can  be  utilized  for  hauling  and  belt  work 
when  not  employed  as  a  road  roller.  Economy  is  a 
strong  point  in  favor  of  the  gas  operated  road  roller. 
As  machines  of  this  kind  carry  a  supply  of  fuel  and 
cooling  water  sufficient  for  practically  a  day's  opera- 
tion, no  water  wagon  or  coal  wagon  is  needed  to  act  as 
a  tender  as  is  necessary  with  the  steam  tractor. 

A  hitch  by  which  a  powerful  enough  gas  tractor  may 
be  utilized  to  haul  three  road  scrapers  or  graders  at  a 
time  is  clearly  outlined  at  Fig.  186.  This  makes  it 
possible  to  finish  a  large  amount  of  work  in  one  trip, 
as  practically  the  entire  width  of  the  average  roadway 
may  be  treated  at  the  same  time.  The  machine  nearest 
the  ditch  line  is  attached  directly  to  one  end  of  the 
drawbar  by  means  of  a  pole  while  the  others  are  pulled 
by  half-inch  steel  cables  as  indicated.  The  method 
by  which  the  road  scrapers  are  made  to  follow  the 
tractor  is  also  clearly  shown.  The  same  hitch  as  out- 
lined would  be  practical  with  any  other  machine  of 
which  a  number  must  be  hauled  at  the  same  time, 
such  as  harvesters,  etc. 

The  marked  advantage  of  the  gas  tractor  in  road 
work  is  that  the  change  speed  gear  feature  found  on 
most  gas  tractors  enables  them  to  do  very  heavy  scrap- 


Tin:  Modern  Gas  Tractor 


415 


ing.  By  operating  on 
one  of  the  lower  speeds 
a  scraper  blade  full  can 
be  handled  both  on  the 
level  and  when  ascend- 
ing hills,  and  it  is  never 
necessary  to  stop  the 
machine  and  drop  part 
of  the  load  as  is  the 
case  with  a  horse-drawn 
scraper  when  a  heavier 
cut  is  taken  than  can 
be  carried  through  by 
horses.  When  a  tractor 
is  used  for  road  work 
the  character  of  the 
work  is  always  better 
than  when  horses  are 
employed,  because 
there  are  no  irregular- 
ities in  the  cut  as  are 
invariably  present 
when  a  scraper  is  drawn 
by  animal  power. 

The  lower  cost  of  op- 
erating a  road  scraper 
by  tractor  as  compared 
with  the  cost  of  doing 
this  work  by  horses  is 
probably  the  greatest 
point  in  favor  of  the 
gasoline  tractor.  The 
road  commissioners 
of   a   New   York   town 


41G 


Thk  Modern  Gas  Tractor 


owning  and  operating  a  gas  tractor"  state  that  the 
weekly  expense  when  using  six  horses  on  the  road  machine 
has  been  $84.00  per  week  (including  two-horse  team 
hire  at  the  rate  of  $4.00  each  per  day).  They  state  that 
when  operating  the  scraper  by  means  of  the  tractor 
they  accomplish  one-third  more  work  at  a  total  weekly 
expense,  including  cost  of  gasoline,  cylinder  oil  and 
operators,  of  $36.00,  or  a  net  saving  of  $48.00  per  week 
plus  one-third  more  work.     To  reduce  this  to  the  basis 


Fig.  187. — Special  Wagon  Adapted  to  be  Used  in  Train  Hauled 
by  Gas  Tractor. 


of  the  cost  for  an  equal  amount  of  work,  the  hire  of 
one  additional  team  should  be  added,  in  which  case 
the  saving  effected  by  the  tractor  is  $72.00  per  week. 
These  figures  cover  the  total  cost  of  the  work  based 
on  actual  working  conditions  throughout  the  season 
(but  not  including  interest  and  depreciation  on  machin- 


The  Moderx  Gas  Tractor 


417 


Fig.  188. — Combination  Road  Roller  and  Tractor,  an  Extremely 
Useful  Machine  for  General  Contractors  or  Municipal  Use. 
A — Machine  With  Roller  for  Steering  and  Auxiliary  Rims 
on  Traction  Members.  B — Roller  Removed  From  Front 
and  Wheels  Substituted,  Making  Practical  Tractor  for 
Road  or  Field  Work. 


418  The  Modern  Gas  Tractor 

ery),  the  quality  of  the  work  being  better  than  would 
be  obtained  by  horse  power. 

The  tractor  referred  to  has  also  been  used  by  the 
town  chiefly  for  hauling  gravel  and  crushed  stone  and 
doing  other  work  of  this  nature,  but  in  this  particular 
instance  has,  during  the  late  fall  and  winter,  been  a 
source  of  revenue  to  them  as  it  has  been  rented  to 
private  parties  for  operating  machines  by  belt  power 
and  also  for  ditching. 

A  tractor  can  be  used  successfully  for  hauling,  and 
under  average  conditions  on  dirt  or  gravel  roads,  20,000 


Fig.  189. — Harvesting    With    Avery    Gas    Tractor    in    North 

Dakota. 

pounds,  exclusive  of  the  weight  of  the  machine,  can  be 
hauled  with  a  tractor  of  but  15  horse-power.  On  mac- 
adam roads,  or  good  gravel  roads,  the  hauling  capacity 
is,  of  course,  increased.  As  a  rule,  the  character  of  the 
road  surface  greatly  affects  the  hauling  capacity.  On  a 
plank  road  but  100  pounds  draft  per  ton  hauled  is  neces- 
sary. Upon  macadam  road  it  will  require  from  150 
to  225  pounds  draft  to  haul  one  ton.  The  amount  of 
power   necessary   increases   to    about   300    pounds    per 


The  Modern  Gas  Tractor 


419 


4iMi  The  Modern  Gas  Tractor 

ton  on  a  gravel  road  and  an  average  of  about  400  pounds 
puJl  per  ton  on  a  common  dirt  road.  Wagons  intended 
to  be  pulled  by  tractors  are  of  special  form  and  are 
made  so  they  can  be  coupled  up  in  a  train.  As  the 
width  of  wheels  has  material  bearing  upon  the  hauling 
capacity,  most  wagons  adapted  for  use  on  soft  roads 
have  wide  wheels.  Such  a  vehicle  with  a  platform 
body  is  shown  at  Fig.  187. 

The  construction  of  a  combined  gas  tractor  and 
road  roller  is  clearly  shown  at  Fig.  188.  The  view 
at  A  shows  the  roll  in  place  under  the  front  end  of  the 
machine  and  the  auxiliary  smooth  steel  tires  attached 
over  the  grouters  of  the  driving  wheels.  A  tractor 
designed  for  use  either  as  a  road  roller  or  tractor  usually 
has  a  different  method  of  front  suspension  than  is 
commonly  employed  on  tractors  in  order  to  use  a  roller 
of  larger  diameter  than  usually  allowed  for  the  front 
wheels.  At  B  a  one-piece  axle  carrying  two  wheels 
has  been  substituted  for  the  roll  assembly  and  the 
smooth  steel  tires  have  been  removed  from  the  traction 
members  so  that  the  grouters  on  the  wheels  again  become 
effective.  This  makes  possible  the  use  of  the  machine 
as  a  tractor.  The  change  from  one  to  the  other  can  be 
readily  effected  on  the  road,  so  the  general  contractor 
finds  the  combination  machine  a  very  good  investment. 

With  the  development  of  the  successful  binder  hitch, 
it  has  been  found  practical  to  use  the  gas  tractor  for 
power  in  harvesting.  Six-foot  binders  require  from  three 
hundred  to  five  hundred  pounds  draft  to  pull  them  at 
a  speed  high  enough  to  do  good  work.  Mowing  machines 
without  binder  attachment  and  capable  of  taking  a 
five  or  six-foot  cut  are  usually  operated  with  two  horses 
and  therefore  require  a  draft  of  about  250  to  300  pounds 
when  hauled  by  a  tractor.    This  value  may  be  increased 


The  Modern  Gas  Tractor 


421 


422 


The  Modern  Gas  Tractor 


largely  by  dull  knives,  binding  or  tight  boxes,  or  when 
cutting  highly  resistant  grains  or  grass.  Timothy  is 
the  hardest  crop  to  cut  and  takes  the  most  power. 
As  almost  all  mowers  run  at  speeds  that  are  variable, 
it  is  difficult  to  give  exact  figures  regarding  the  power 
consumption  of  mowing  machines  or  binders.  As  a 
high  speed  must  be  maintained  on  a  binder,  it  is  common 
practice  to  use  three  horses,  whereas  two  are  sufficient 
for  the  mower.  As  the  machines  work  to  best  advantage 
at  a  speed  of  about  two  and  one-half  miles  per  hour, 


Fig.  192. — Gas  Tractor  Not  Only  Cuts  but  Stores  the  Fodder. 

it  will  be  apparent  that  the  gas  tractor  is  particularly 
well  adapted  for  use  in  harvesting,  as  even  the  lower 
powered  forms  are  capable  of  pulling  three  mowing 
machines  at  this  speed.  The  views  at  Fig.  189  and 
Fig.  190  show  the  application  of  the  gas  tractor  in 
harvesting  work. 

The  gas  tractor  is  particularly  suitable  for  threshing 
after  the  grain  is  harvested,  owing  to  the  ease  with 
which  it  can  be  utilized  as  a  stationary  power  plant  for 


The  Modern  Gas  Tractor  423 

work  with  the  belt.  The  advantages  in  threshing  have 
been  considered  at  length  in  one  of  the  earlier  chapters, 
so  it  is  merely  necessary  in  this  instance  to  briefly 
enumerate  its  advantages.  At  Fig.  191  an  entire  thresh- 
ing outfit  is  shown  ready  for  the  road.  The  gas  tractor 
can  haul  the  threshing  machine  and  the  attendant 
train  of  wagons  any  distance,  and  when  the  scene  of 
activities  is  reached  it  is  but  the  work  of  a  few  moments 
to  connect  the  tractor  with  the  machine  to  be  operated 
by  means  of  a  long  driving  belt  as  shown  in  the  lower 
portion  of  the  illustration.  It  will  be  apparent  that 
the  tractor  is  not  only  capable  of  hauling  the  imple- 
ments and  wagons  necessary  to  any  point,  but  it  can 
also  be  utilized  successfully  for  driving  the  machinery 
when  it  reaches  its  destination. 

The  power  needed  to  operate  various  forms  of  machines 
under  belt  as  given  by  the  International  Harvester 
Company  follows: 

MACHINE.  HORSE-POWER. 

4-Roll  Deering  Husker  and  Shredder 12 

6-Roll  Deering  Husker  and  Shredder 15 

4-Roll  McCormick  Husker  and  Shredder 12 

6-Roll  McCormick  Husker  and  Shredder 15 

8-Roll  McCormick  Husker  and  Shredder 20 

10-Roll  Piano  Husker  and  Shredder 20 

24"  x  40"  Thresher 15 

28"  x  44"  Thresher 20 

28"  x  48"  Thresher 20 

32"  x  52"  Thresher 25 

36"  x  56"  Thresher 25 

4-Hole  Keystone  Sheller 12 

6-Hole  Keystone  Sheller 12 


424  The  Modern  Gas  Tractor 

As  the  ordinary  tractor  power  plant  will  develop 
its  full  brake  horse-power  when  used  in  belt  work  it 
will  be  apparent  that  even  the  lighter  traction  engines 
may  be  used  successfully  for  operating  the  machinery 
that  must  be  run  by  belt.  The  utility  of  the  tractor 
for  this  purpose  is  clearly  indicated  at  Fig.  192.  Here 
the  machine  has  been  placed  outside  of  the  barn  and 
convenient  to  the  material  to  be  cut  and  elevated  into 
the  loft.  The  tractor  is  run  to  where  the  work  is  to 
be  done  and  a  simple  belt  connection  with  any  machine 
serves  to  drive  it. 


Fig.  193. — Holt   Caterpillar   Tractor   Demonstrates   Its   Worth 
In  Swampy  Ground. 

The  tractor  may  often  be  used  under  conditions  that 
on  first  consideration  would  seem  impossible.  At  Fig. 
193  the  utility  of  the  Caterpillar  Tread  Tractor  in 
swampy  ground  is  clearly  demonstrated  and  it  should 
be  remembered  that  on  land  of  this  nature  it  is  practi- 
cally impossible  to  work  horses.  The  illustration  at 
Fig.  194  shows  another  unusual  application  where  the 
gas  tractor  has  successfully  replaced  horses.  The  work 
of  hauling  logs  over  the  snow  covered  and  rough  roads 


The  Modern  Gas  Tractor 


425 


of  the  lumber  regions  is  economically  done  by  the 
gas  traction  engine  and  the  train  of  wagons  that  it  hauls. 
The  view  at  Fig.  195  clearly  demonstrates  that  a  gas 
tractor  can  be  operated  in  very  deep  snow,  and  when 
one  considers  the  height  of  the  driving  wheels  it  will 
be  apparent  that  a  tractor  can  be  used  over  roads 
that  would  seriously  impede  other  forms  of  self-pro- 
pelled vehicles. 

Home=made   Gas   Tractors. — A  discussion  of  gas 
tractor    construct  on    would    not    be    complete    without 


Fig.  194. — The  Modern  Gas  Tractor  Makes  Hauling  of  Heavy 
Logs  a  Commercial  Proposition. 

reference  to  some  of  the  ingenious  outfits  that  have 
been  built  by  farmers  for  their  own  use.  The  machine 
at  Fig.  196  is  a  light  construction  in  which  a  circular 
saw  outfit  has  been  made  self-propelling  Only  one 
of  the  rear  wheels  is  driven,  this  being  operated  by 
gearing  which  in  turn  receives  the  power  of  the  engine 
through  a  leather  belt.  Tightening  this  belt  serves 
to  transmit  the  power  from  the  engine  to  the  counter- 
shaft and  from  thence  to  the  driven  wheel.  When  the 
belt  tension  is  released,  the  engine  may  run  free  of 
the  wheel.     The  vehicle  is  directed  by  a  steering  wheel 


420 


The  Modern  Gas  Tractor 


which  operates  the  independently  pivoted  front  wheels 
which  are  joined  by  a  tiebar  in  just  the  same  manner 
as  in  the  Ackerman  axle.  The  circular  saw  is  mounted 
at  the  front  end  of  the  machine  and  is  adapted  to  be 
driven  from  the  engine  when  the  tractor  has  reached 
its  destination. 

Another  home-made  tractor  of  substantial  construc- 
tion in  which  a  single  cylinder  stationary  type  engine 


Fig.  195. — An  Aultman  &  Taylor  Tractor  Operating  in  Deep 
Snow,  Shows  That  All  the  Year  Round  Service  May  be 
Obtained  From   the  Modern  Gas   Tractor. 

is  utilized  for  power,  is  shown  at  Fig.  197.  The  drive 
is  by  means  of  a  belt  from  the  engine  pulley  to  a  pulley 
placed  on  a  countershaft  mounted  directly  over  the 
front  axle.  A  sprocket  is  secured  to  this  shaft  between 
the   two   bearings,    and    this    drives  a   larger   sprocket 


The  Modern  Gas  Tractor 


427 


attached  to  a  differential  gear  of  a  cross  shaft.  The 
rear  wheels  are  driven  from  this  cross  shaft  by  chain 
and  sprocket  connection.  The  front  axle  is  a  one-piece 
type  and  is  operated  by  a  chain  steering  gear  and  the 
usual  form  of  hand  wheel. 

It  is  not  considered  practical  for  the  average  farmer 
to  attempt  to  build  a  tractor,  and  most  of  the  machines 
constructed  have  not  been  as  practical  as  those  built 


Fig.  196. — Ingenious  Home-made  Light  Tractor  Saw  Construct- 
ed bv  F.  J.  Jantz  of  Hillsboro.  Kansas. 


by  experienced  manufacturers  with  proper  facilities. 
The  machines  illustrated  are  presented  to  show  what 
may  be  accomplished  by  the  handy  man  who  is  able  to 
utilize  odds  and  ends  and  old  implement  parts  that 
ordinarily  would  be  considered  as  junk  and  contrive 
a  machine  that  is  capable  of  doing  useful  work.  Before 
the  tractor  had  been  developed  to  the  point   of  per- 


42S 


The  Modern  Gas  Tractor 


fection  that  now  obtains,  many  home-made  machines 
were  used  for  various  purposes.  With  the  advent  of 
the  improved  gas  tractors  the  farmer  has  been  able 
to  obtain  machinery  that  would  answer  his  purpose 
at  a  much  lower  cost  than  if  he  attempted  to  build 
a  machine  following  his  own  ideas. 


Pig.  197. — Home-made  Gas  Tractor  Outfit  Built  by  John  H. 
Sands,  Cavalier,  North  Dakota. 

Auto  Tractor  Attachment. — The  auto-tractor  is 
an  attachment  of  recent  development,  designed  to  be 
attached  to  the  standard  types  of  automobiles  and  to 
make  it  possible  to  use  the  self-propelled  vehicles  in 
performing  the  various  kinds  of  farm  work  where  mech- 


The  Modern  Gas  Tractor 


429 


430  The  Modern  Gas  Tractor 

anical  power  may  be  utilized.  The  general  construction 
may  be  readily  determined  by  examining  Fig.  198, 
which  shows  the  tractor  attachment  partly  in  place 
under  the  auto  chassis.  The  illustration  Fig.  199  shows 
a  side  view  of  an  automobile  to  which  this  attachment 
has  been  fitted,  while  that  at  Fig.  200  is  a  rear  view  of 
the  same  machine  showing  the  tractor  hauling  a  three 
bottom  gang  plough. 

This  device  is  of  such  form  that  it  may  be  attached  to 
any  automobile  of  standard  tread  and  utilizes  the  auto- 
mobile engine  and  driving  system  which  can  be  made 
to  do  the  work  of  either  a  stationary  or  traction  engine. 
The  power  is  transmitted  to  the  tractor  attachment  by 
means  of  small  pinions  fastened  to  the  rear  hubs  of  the 
motor  car.  These  mesh  with  a  train  of  gears  which  gives 
a  speed  reduction  and  which  multiplies  the  available 
drawbar  horse-power  of  the  automobile  twelvefold. 
The  machine  uses  its  own  power  to  load  itself  in  that  it 
draws  the  tractor  attachment  into  place  under  the  car. 

A  pair  of  supporting  members  called  "chairs"  are  at- 
tached to  the  axle  which  are  designed  to  rest  on  the 
frame-members  of  the  tractor  so  as  to  lift  the  wheels  of 
the  automobile  from  the  ground.    » 

It  is  claimed  that  from  either  the  standpoint  of  initial 
investment  or  operating  cost  this  machine  is  very  eco- 
nomical. The  owner  of  an  automobile  may  secure  many 
of  the  advantages  offered  by  the  gasoline  tractor  with  an 
additional  investment  of  about  one-fourth  what  a  gas- 
oline tractor  would  cost.  The  tractor  attachment  is 
light  in  weight  and  the  wheels,  which  are  six  feet  in  di- 
ameter, make  it  possible  to  operate  an  automobile  with 
a  tractor  attachment  successfully  on  soft  or  wet  ground. 
The  rear  wheels  of  the  automobile  are  raised  clear  of 
the  ground  and  it  is  stated  that  when  in  position  on  the 


The  Modern  Gas  Tractor  431 

tractor    and    in  operation   there   is   less   strain   on  the 
automobile  than  when  traveling  over  country  roads. 

In  operation,  the  automobile  with  tractor  attachment 
is  as  easy  to  control  as  a  one  speed  tractor  because  most 
of  the  driving  is  done  entirely  with  the  change  speed 
lever  in  the  high  speed  or  direct  drive  position.  The 
direct  drive  through  the  automobile  gearing  to  the 
automobile  rear  wheels  differs  only  in  one  respect  from 
conditions  present  in  regular  road  travel   and   that  is 


Fig.  199. — Side   View   of   Automobile,    Equipped    With   Auto- 
tractor  Attachment. 

that  the  power  is  applied  at  the  face  of  the  pinion  secured 
to  the  hub  instead  of  at  the  tire.  The  revolving  rear 
wheels  act  as  flywheels  and  make  for  smoother  operation. 
The  gearing  is  designed  so  that  two  speeds  are  available, 
one  of  two  miles  per  hour  and  one  of  four  miles  per  hour. 
As  is  true  of  the  conventional  form  of  tractor  the  lower 
speed  is  used  when  pulling  ploughs  or  doing  other  work 
where  the  full  capacity  of  the  machine  is  needed.  The 
high  speed  is  utilized  in  moving  wagon  trains  and  similar 
road  work. 


432  The  Modern  Gas  Tractor 

The  gearing  is  so  proportioned  that  when  the  tractor 
is  moving  at  a  speed  of  two  miles  per  hour  the  automobile 
power  plant  is  running  at  from  800  to  1000  revolutions 
per  minute.  This  speed  is  the  normal  at  which  the  aver- 
age motor  can  operate  continuously  without  strain  and 
at  the  same  time  deliver  practically  its  full  horse-power. 
The  attachment  will  fit  automobiles  ranging  from  twenty 
to  ninety  horse-power  and  as  it  can  be  attached  or  detached 
in  very  few  minutes  it  does  not  interfere  with  the  ordin- 
ary use  of  the  automobile.  After  a  day's  work  in  the  field 
the  large  traction  wheels  may  be  uncoupled  and  the  de- 
vice left  in  the  field  ready  for  the  next  day's  work  while 
the  automobile  conveys  the  workmen  to  their  destination. 

The  auto-tractor  is  provided  with  a  pulley  attachment 
which  permits  it  to  be  used  as  a  stationary  power  plant 
and  will  operate  all  kinds  of  farm  machinery  from  a 
grindstone  to  a  threshing  machine.  Among  some  of  the 
refinements  of  detail  that  are  apparent  are  an  auxiliary 
cooling  system  on  the  tractor  attachment  which  insures 
that  the  automobile  motor  will  not  overheat  on  account 
of  the  low  vehicle  speed.  A  fan,  pump  and  radiator  are 
placed  on  the  tractor  attachment  and  water  is  passed 
through  the  auxiliary  radiator  as  well  as  that  of  the  car 
by  means  of  simple  connections  and  the  motor  is  thus 
properly  cooled  under  all  conditions  of  weather.  A  stor- 
age tank  holding  twenty-four  gallons  is  connected  into 
the  cooling  system  and  an  all-day  run  without  additional 
water  is  possible. 

The  amount  of  work  that  can  be  done  with  the  tractor 
attachment  depends  entirely  upon  the  size  of  the  engine 
in  the  automobile  to  which  it  is  applied.  The  following 
table  shows  the  relation  between  the  horse-power  rating 
of  the  automobile  and  the  number  of  horses  it  will  re- 
place in  field  work. 


The  Modern  Gas  Tractor  433 

Automobile  Rating.  Farm  Horses  Replaced. 

20  Horse-power 4  to    6 

30  "  6  to    9 

40  "  10  to  14 

50  "  14  to  18 

60  "  18  to  22 

75  "  22  to  30 

90  "  30  to  36 

As  previously  mentioned,  the  automobile  is  carried 
almost  entirely  by  the  steel  frame  of  the  tractor  attach- 
ment on  which  the  rear  axle  rests  and  which  is  fastened 
rigidly  to  the  front  axle  so  that  the  power  exerted  at  the 
traction  wheels  is  distributed  evenly  on  the  entire  auto- 
mobile chassis.  It  is  claimed  that  the  device  has  been 
examined  carefully  by  automobile  manufacturers  and 
engineering  experts  and  that  no  criticism  was  offered 
after  a  close  study  of  the  principles  of  operation  had  been 
made.  It  is  believed  that  this  attachment  will  serve  to 
still  further  promote  the  sales  of  automobiles  to  farmers. 
Future  Possibilities. — The  field  of  usefulness  to 
which  the  tractor  can  be  applied  is  enormous.  Over 
ten  million  horses  are  in  use  in  the  big  farming  States 
or  agricultural  purposes.'  If  the  farmers  of  these 
States  would  replace  but  one  out  of  five  horses  or  20 
per  cent,  it  is  claimed  that  there  is  a  market  for  over 
sixty  thousand  tractors  of  the  medium  power  class, 
not  to  mention  the  large  sale  and  great  market  for 
the  smaller  machines  designed  to  do  the  work  of  three 
or  four  horses  on  the  small  farm. 

The  tractor  has  demonstrated  its  worth  and  is  prac- 
tical in  construction.  It  has  demonstrated  that  it  will 
cut  the  cost  of  production  of  all  farm  products  and 
will  reduce  the  cost  of  marketing  as  well  because  the 
road    to    market    is    shortened    by    mechanical    power. 


434 


The  Modern  Gas  Tractor 


Fig.  200. — Rear   View   of   Automobile   With   Auto-tractor 
Attachment,  Showing  Practical  Application  in  Ploughing. 

One  authority  says,  "The  tractor  is  at  the  dawn  rather 
than  at  the  twilight  of  its  development."  It  has  develop- 
ed from  a  monstrous,  inefficient  toy  into  a  powerful 
and  efficient  servant. 

It  is  not  only  on  the  farm  that  the  tractor  can  be 


The  Modern  Gas  Tractor  435 

used  to  advantage.  In  contracting  and  construction 
work  its  uses  are  unlimited.  Many  deposits  of  stone 
have  been  converted  into  surfacing  material  for  high- 
ways by  its  aid.  It  has  been  used  in  building  and  main- 
taining roads,  in  digging  irrigation  canals,  and  filling 
drainage  ditches.  It  has  hauled  machinery  to  the 
mines,  brought  the  ore  to  the  surface  and  carried  it 
to  the  railroad  or  smelting  plant.  Enormous  logs  have 
been  taken  from  forests  where  big  teams  of  horses  could 
not  be  handled.  It  has  been  used  even  in  the  field  of 
modern  amusement  enterprises,  and  a  number  of  the 
big  tent  shows  are  shifting  their  heavy  trucks  with  a 
traction  engine  which  also  runs  a  dynamo  and  fur- 
nishes power  for  electrically  lighting  the  tents  during 
the  evening  exhibition. 

The  performance  of  the  tractor  in  the  past  is  but  a 
promise  of  what  it  may  accomplish  in  the  future.  Much 
depends  on  the  education  of  the  farmer.  It  is  not 
natural  to  assume  that  one  who  has  been  familiar  with 
horses  since  childhood  will  be  ready  to  replace  these 
with  mechanical  power  about  which  he  knows  compara- 
tively nothing.  As  the  tendency  of  modern  farming 
is  to  make  it  more  scientific  and  an  engineering  proposi- 
tion, the  farmer  of  the  future  will  be  trained  in  solving 
mechanical  problems.  While  it  is  to  the  younger  ele- 
ment that  we  must  look  for  substantial  progress  and 
ready  adoption  of  new  methods,  much  will  be  accom- 
plished by  even  the  conservative  old-time  farmer  who 
will  realize  the  advantages  of  mechanical  traction,  study 
the  applications  and  forms  of  gas  tractors  best  suited 
to  his  work  and  link  the  invaluable  experience  of  the 
past  with  the  progressive  ideas  of  the  future. 


CHAPTER  XI. 

MISCELLANEOUS  RULES  AND  FORMULA. 

A  Collection  of  Useful  Rules,  Tables  and  Formulae  That  Will 
Prove  of  Value  to  the  Student,  Mechanic  or  Farmer, 
These  Include  Additional  Rules  for  Figuring  Horse-power, 
for  Estimating  the  Capacity  of  Tanks,  Strength  of  Mate- 
rials, U.  S.  and  Foreign  Conversion  Tables  ?nd  Other 
Interesting  Information  of  a  Miscellaneous  Nature. 


437 


USEFUL  RULES,  TABLES 
AND  FORMULAE 


RULES  FOR  CALCULATING  HORSE=POWER. 

To  calculate  the  horse-power  of  any  4-cycle  motor, 
the  following  general  formula  is  always  used,  this  giving 
the  output  of  a  single  cylinder  and  must  be  multiplied 
by  the  number  of  cylinders  for  multiple  cylinder  engines. 

PLAR  _ 

33000x2  ~  H'  P' 

In  which 

P=  pounds  per  square  inch. 

L= length  of  stroke  in  feet. 

A = piston  area  in  inches. 

R=the  number  of  revolutions  per  minute. 
The  pressure  in  any  engine  is  assumed  to  be  a  mean 
effective  pressure  or  average  pressure  throughout  the 
stroke,  and  is  written  M.  E.  P.  For  gasoline  engines 
of  the  usual  4-cycle  automobile  type  this  pressure  can 
be  assumed  at  between  75  and  100  pounds,  it,  of  course, 
varying  with  the  general  design.  The  actual  M.  E.  P. 
of  an  engine  which  has  already  been  built  can  be  deter- 
mined by  the  manograph,  which  records  by  means  of 
a  streak  of  light  the  outline  of  the  indicator  card,  which, 
if  desired,  can  be  permanently  retained  by  means  of 
a  photographic  plate.  It  can  also  be  determined  at 
speeds  under  500  R.  P.  M.  by  diagrams  produced  by 
ordinary  steam  engine  indicators,  but  these  are  not 
accurate  when  used  with  high  speed  gasoline  engines, 
the  manograph  being  far  superior. 

439 


440 


The  Modern  Gas  Tractor 


FORMULA  FOR  INDICATED  HORSE=POWER. 

D2XLXnXM.  E.  P.XR.  T    TT    „ 

gen/Vw.  ~  I-  H-  p-   4-eycle   X   Constant     for 

5o0,000 

2-cyele  engines,  275,000. 

D2=Bore  of  cylinders  in  inches  squared. 

L  =  Stroke  of  piston  in  inches. 

R  =  Revolutions  per  minute  of  crankshaft. 

n  =  Number  of  cylinders. 

M.  E.  P.  =  Mean  effective  pressure. 
Mean  Effective  Pressure  increases  as  the  compression 
and  decreases  as  the  R.  P.  M.  augment.  The  thermal 
efficiency  of  a  motor  is  the  ratio  between  the  work 
done  and  the  thermal  energy  contained  in  the  fuel  con- 
sumed and  is  between  15  to  30  per  cent.  The  mechanical 
efficiency,  by  which  is  understood  the  ratio  between  the 
work  actually  done  to  the  energy  expended  on  the  piston 
by  the  expanding  gases,  is  approximately  85  per  cent. 

MEAN  EFFECTIVE  PRESSURES  OF  TYPICAL  AUTO 
MOTORS. 


Make. 

Cylinders. 

H.  P. 

R.  P.  M. 

M.  E.  P. 

National. . . 

Four  5x511/i6" 

j      64 
j     54 

1,400 
1,055 

81.1 
90.9 

Pierce 

Six      4x4%" 

j     44.5 
(     30.9 

1,263 
800 

76.1 

85.4 

Rambler. . . 

Four  5x5  H" 

43.5 

1,091 

73.1 

Thomas. . . 

Six      4^x53^" 

49 

1,091 

76.0 

Thomas.  .  . 

Six      4Mx53^" 

34 

700 

83.4 

S.  A.  E.  HORSE=POWER  FORMULA. 

The  formula  adopted  is  2.5  '  and  based  on  1,000 
feet  per  minute  piston  speed.  D  is  the  cylinder  bore, 
N  the  number  of  cylinders,  and  2.5  a  constant,  based 
on  the  average  view  of  the  Mechanical  Branch  as  to 
a  fair  conservative  rating. 


The  Modern  Gas  Tractor 


441 


TABLE  OF  HORSE-POWER  FOR  USUAL  SIZES  OF 
MOTORS,  BASED  ON  S.  A.  E.  FORMULA. 


Bore. 

Horse 

-power. 

Inches. 

M  M 

1  Cyl. 

2  Cyls. 

4  Cyls. 

6  Cyls. 

2V2 

64 

2H 

5 

10 

15 

1% 

68 

2% 

5V2 

11 

16^ 

2% 

70 

3 

6 

127.o 

1875 

2% 

73 

37,6 

6M 

13M 

19J/8 

3 

76 

3Vo 

775 

1475 

21»/« 

3K 

79 

3»/« 

7"/,6 

157s 

237.6 

3M 

83 

4M 

sy2 

167.o 

257s 

3^ 

85 

47.6 

QVs 

18M 

277s 

3H 

89 

47io 

94/5 

197s 

297s 

Wz 

92 

5^ 

103^ 

20  H 

317o 

3% 

95 

5^ 

11M 

22  y2 

33^ 

Z7A 

99 

6 

12 

24 

367.6 

4 

102 

67s 

127s 

257s 

387s 

±Vs 

105 

6»/.6 

13^ 

27}4 

407,o 

4J4 

108 

7H 

14^ 

287.o 

437s 

4H 

111 

7^ 

157.6 

30^ 

4517.6 

4H 

114 

8V10 

167s 

3275 

4875 

4^ 

118 

87.6 

173^ 

3434 

517s 

4^ 

121 

9 

18 

367.0 

547,0 

±H 

124 

9V2 

19 

38 

57 

5 

127 

10 

20 

40 

60 

5K 

130 

10  y2 

21 

42 

63 

5J4 

133 

11 

22 

44710 

667s 

5^ 

137 

117.6 

23 

46 

697.0 

442 


The  Modern  Gas  Tractor 


Bore. 

Horse- 

Dower. 

Inches. 

M/M 

1  Cyl. 

2  Cyls. 

4  Cyls. 

6  Cyls. 

sy2 

140 

lZVxo 

24V5 

48V, 

72V, 

55A 

143 

12  V8 

25V.6 

50^ 

75"/,, 

5% 

146 

13^ 

2&y2 

53 

79  K 

5VS 

149 

13»A, 

w  y8 

55^ 

82Vio 

6 

152 

14V, 

284/5 

57»/, 

867, 

To  simplify  reading  of  the  above,  the  horse-power 
figures  are  approximate,  but  correct  within  one-six- 
teenth.   

A  SIMPLE  HORSE=POWER  FORMULA. 

H.  P.  =  PLD2R  with  three  decimal  places  pointed  off. 
In  which     P=Mean  effective  pressure. 
L=  Stroke  in  inches. 
D= Diameter  in  inches. 
R= Number  of  cylinders. 
The  M.  E.  P.  can  be  assumed  or  taken  from  tables. 
A  speed  of  1,000  R.  P.  M.  is  the  only  assumption  made, 
and  the  formula  takes  into  consideration  pressure,  bore 
and  stroke,  and  is  the  simplest  form  to  which  the  writer 
has  yet  been  able  to  reduce  the  H.  P.  formula,  still  re- 
taining all  the  essentials. 

WELL=KNOWN  CLUB  AND  ASSOCIATION 
HORSE=POWER  FORMULAE. 

For  easy  comparison  of  one  car  with  another  and  for 
facilitating  handicapping  at  hill  climbs  and  race  meets, 
the  following  formulae  have  been  given  out  by  clubs 
and  associations.     For  the  sake  of  uniformity,  let: 

D2=  Square  of  piston  diameter  in  inches. 

L  =  Stroke  in  inches. 

R  =  Revolutions  per  minute. 

N  =  Number  of  cylinders. 


The  Modern  Gas  Tractor 


443 


HORSE=POWER  FORMULA,  4=CYCLE  ENGINES. 

D2N 


A.  L.  A.  M.  Formula,  H.  P.= 
Roberts  Formula,  H.  P.= 
Royal  Auto  Club,  H.  P.= 


2.5 

D2LNR 

"  1800 

(D+L)2N 
9.92 


Fig.  201.— Plan  of  Easily  Constructed  Prony  Brake  for  Making 
Power  Tests. 


4-U 


Tiik  Modern  Gas  Tractor 


TABLE  FOR  CALCULATING  B.  H.  P.  OF  AN 
ENGINE. 

KNOWING    THE    BRAKE    ARM    LENGTH,    SPEED    AND    PULL    ON    THE 

SCALES.        (c.  T.   SWART.) 


B.  H.  P.  = 


2X3.1416XRXPXN 
33,000 


R=  Brake  arm  in  feet. 
P=Pull  on  scales  in  pounds. 
N  =  Revolutions  per  minute. 


Values  in  table  = 


2X3.1416X100XRXP 
33,000 


The  figures  in  this  table  are  for  a  speed  of  100  revo- 
lutions per  minute;  therefore  when  readings  are  taken 
for  any  other  speed,  the  answer  found  in  the  table  must 
be  multiplied  by  the  actual  speed  divided  by  100. 


Pull 
in 

Arm  in  Feet. 

Pounds 

1 

1M 

iy2 

m 

2 

2M 

2H 

2H 

3 

5 

0.095 

0.119 

0.142 

0.166 

0.190 

0.214 

0.238 

0.2610.285 

10 

0.190 

0.238 

0.285 

0.332 

0.381 

0.428 

0.475 

0.5220.570 

15 

0.285 

0.357 

0.428 

0.498 

0.570 

0.642 

0.713 

0.7830.785 

20 

0.380 

0.476 

0.570 

0.666 

0.760 

0.856 

0.950 

0.14 

1.15 

25 

0.475 

0.595 

0.713 

0.830 

0.950 

1.07 

1.19 

1.31 

1.43 

30 

0.570 

0.713 

0.885 

0.996 

1.15 

1.28 

1.43 

1.57 

1.71 

35 

0.665 

0.833 

1.00 

1.16 

1.33 

1.49 

1.66 

1.83 

2.00 

40 

0.760 

0.952 

1.14 

1.33 

1.52 

1.71 

1.91 

2.09 

2.28 

45 

0.855 

1.07 

1.28 

1.49 

1.71 

1.93 

2.14 

2.35 

2.56 

50 

0.950 

1.19 

1.43 

1.66 

1.90 

2.14 

2.38 

2.61 

2.85 

55 

1.05 

1.31 

1.57 

1.83 

2.09 

2.35 

2.61 

2.87 

3.14 

60 

1.15 

1.43 

1.71 

2.00 

2.28 

2.57 

2.85 

3.13 

3.42 

Table  concluded  on  next  page. 


The  Modern  Gas  Tractor 


445 


Pull 
in 

Arm 

i;i  Feet. 

Pounds 

1 

IX 

\ia 

I    1% 

2 

2H 

2V2 

2?4 

3 

65 

1.24 

1.55 

1.85 

2.16 

2.47 

2.78 

3.09 

3.39 

3.71 

70 

1.33 

1.66 

2.00 

2.33 

2.66 

3.00 

3.33 

3.66 

4.00 

75 

1.43 

1.78 

2.14 

2.49 

2.85 

3.21 

3.57 

3.92 

4.27 

80 

1.52 

1.90 

2.28 

i2.66 

3.04 

3.42 

3.80 

4.18 

4.56 

85 

1.62 

2.02 

2.42 

12.83 

3.23 

3.64 

4.04 

4.44 

4.85 

90 

1.71 

2.14 

2.56 

2.99 

3.42 

3.85 

4.28 

4.70 

5.14 

95 

1.81 

2.26 

2.71 

3.16 

3.61 

4.06 

4.52 

4.96 

5.42 

100 

1.90 

2.38 

2.85 

3.32 

3.80 

4.27 

4.75 

5.22 

5.71 

105 

2.00 

2.50 

3.00 

3.50 

4.00 

4.50 

5.00 

5.50 

6.00 

110 

2.10 

2.62 

3.14 

3.65 

4.18 

4.70 

5.23 

5 .  75 

6.27 

115 

2.19 

2.74 

3.28 

3.82 

4.37 

4.92 

5.47 

6.01 

6.66 

120 

2.28 

2.86 

3.42 

3.98 

4.56 

5.14 

5.71 

6.27 

6.85 

ANTI=FREEZING     SOLUTIONS     FOR     COOLING 
SYSTEM. 

There  are  three  principal  agents  used  as  the  basis 
for  anti-freezing  solutions  in  the  cooling  systems  of 
water-cooled  tractor  engines — calcium  chloride,  gly- 
cerine and  alcohol.  The  alcohol  solution  is  usually  pre- 
ferred, especially  since  the  tariff  has  been  removed  on 
denatured  alcohol,  because  it  does  not  damage  the  metal 
of  the  water  jackets,  radiator  or  connections,  and  has 
no  fault  except  that  it  evaporates.  The  other  solutions 
each  have  advantages,  and  users  may  consult  their 
own  preferences  as  to  which  agency  they  prefer. 

Calcium  chloride  (CaCL)  is  a  very  effective  cooling 
agent  but  unless  the  chemically  pure  article  is  used 
there  is  danger  of  corrosion  of  the  metal  with  which 
it  comes  in  contact.  A  solution  of  5  pounds  of  calcium 
chloride  to  each  gallon  of  water  will  not  freeze  at  any 
temperature  above  35  degrees  below  zero.  A  more 
convenient  way  to  prepare  the  solution  is  to  first  make 


446  The  Modern  Gas  Tractor 

a  "saturated  solution"  of  the  calcium  chloride  and 
water,  that  is  mix  with  a  quantity  of  water  warmed 
to  60  deg.  Fahr.  all  the  calcium  chloride  the  water  will 
completely  dissolve,  and  use  equal  parts  of  this  saturated 
solution  and  pure  water  in  the  cooling  system  of  the 
motor.  If  chemically  pure  calcium  chloride  is  used  no 
trouble  will  result.  Chloride  of  lime  (CaOCL)  should 
be  avoided. 

Crude  calcium  chloride  retails  at  about  8  cents  or 
10  cents  a  pound,  while  the  chemically  pure  article 
is  worth  about  25  cents  in  small  quantities. 

Glycerine  is  an  effective  cooling  agent  and  as  it  will 
not  crystalize  in  the  water  jacket  it  is  preferable  in  this 
respect  to  calcium  chloride  and  it  has  the  further  merit 
of  not  requiring  any  renewal  during  the  season  as  it 
does  not  evaporate.  It  is  therefore  only  necessary  to 
add  pure  water  to  replace  that  which  has  evaporated. 
The  main  fault  ascribed  to  gtycerine  is  its  tendency  to 
soften  hose  connections.  Equal  parts  of  glycerine  and 
water  are  used. 

In  using  a  glycerine  solution  care  should  be  taken  to 
thoroughly  cleanse  the  jackets  of  any  residue  of  crystals 
from  calcium  solutions  previously  used  as  this  residue 
will  thicken  and  cloud  the  glycerine  solution. 

Alcohol  can  be  used  in  either  small  or  large  quantities. 
The  freezing  point  of  various  ethyl  alcohol  mixtures 
taken  from  "Physikalisch-Chemische  Tabellen"  are  as 
follows : 


Percentage  of  alcohol  in  water . 

.   2.418 

5.014 

8.105 

17. '.Hi 

Freezing  temperature,  deg.  F.  . 

.30.264 

28.418 

26.213 

18.52 

Percentage  of  alcohol  in  water . 

.36.43 

51.06 

86.22 

Freezing  temperature,  deg.  F .  . 

.   3.20  - 

-10.48  - 

-29.02 

In  addition  to  these  straight  mixtures  of  water  and 
one   anti-freezing   element   there   are   several   combina- 


The  Moderx  Gas  Tractor  447 

tions  of  three  or  more  elements  such  as  1-5  alcohol, 
1-5  glycerine  and  3-5  water;  4  parts  water,  3  parts 
carbonate  potash  and  2  parts  glycerine,  etc. 

A  saturated  solution  of  common  salt  can  also  be  used. 
It  does  not  affect  the  metal  of  the  system  and  remains 
fluid  down  to  0  deg.  Fahr.  An  incrustation,  however, 
occurs  as  the  water  evaporates.  Water  must  be  added 
to  make  up  for  evaporation  when  glycerine,  calcium 
chloride  or  salt  is  used. 


Fig.  202. — A  Simple  Method  of  Determining  Grade  Percentages 
Without  a  Qradometer. 

HOW  TO  ASCERTAIN  THE  GRADE  WITHOUT  A 
QRADOMETER. 

A  method  of  determining  the  percentage  of  a  grade 
on  any  road  without  any  special  instruments  is  here 
given  and  illustrated.  All  that  is  required  is  to  measure 
off  ten  feet  on  any  convenient  stick  and  rest  one  end 
as  shown  in  the  sketch  above,  upon  the  surface  of  the 
road,  being  careful  to  keep  the  stick  horizontal.  This 
can  be  done  by  using  a  spirit  level  or  an  ordinary  bottle 
filled  with  water  allowing  a  bubble  in  the  well-known 
mariner.     Measure  from  the  end  of  the  stick  to  the  road 


448  The  Modern  Gas  Tractor 

surface  and  multiply  by  10,  which  will  give  the  per 
cent  of  the  grade.  The  average  of  several  such  measure- 
ments will  give  fairly  accurate  results. 


TO  REMOVE  RUST. 

Rust  may  be  removed  from  iron  by  immersing  the 
piece  for  several  clays,  or  until  the  rust  has  entirely 
disappeared,  in  water  to  which  a  little  sulphuric  acid 
has  been  added  with  a  piece  of  zinc  firmly  attached  to 
the  iron  so  that  it  makes  a  good  contact.  The  iron  is  not 
attacked  as  long  as  the  zinc  remains  in  contact  with  it. 

Iron  or  steel  may  be  cleaned  of  rust  by  the  use  of 
the  following:  100  parts  stannic  chloride  dissolved  in 
1,000  parts  water.  Add  to  a  solution  containing  2  parts 
tartaric  acid  dissolved  in  1,000  parts  water.  Add  to 
the  mixture  20  cubic  centimeters  indigo  solution  diluted 
with  2,000  parts  of  water.  Clean  the  metal  parts  of 
all  grease,  apply  the  solution  to  the  stained  portions 
for  a  few  seconds,  rub  clean  with  a  moist  cloth,  then 
with  a  dry  cloth,  and  if  desired  then  use  any  good  metal 
polish.  Old  rust  may  be  removed  in  some  cases  by 
rubbing  with  a  paste  consisting  of  equal  parts  of  fine 
tripoli  and  flowers  of  sulphur  thoroughly  mixed  with 
olive  oil. 

Powdered  alum  in  strong  vinegar,  oil  of  tartar,  or 
fine  emery  is  also  used  to  remove  rust.  Kerosene 
or  turpentine  if  left  on  the  stained  or  rusted  portions 
over  night,  will  sufficiently  soften  the  rust  so  that  it 
may  be  removed  by  the  use  of  fine  emery  cloth  followed 
by  a  polishing  powder. 

Rust  spots  on  nickel  can  be  treated  with  grease,  and 
after  several  days  rubbed  with  a  rag  saturated  with  a 
few  drops  of  hydrochloric  acid  in  ammonia.  Parts 
should  be  thoroughly  rinsed,  dried  and  polished. 


The  Modern  Gas  Tractor 


44!  I 


RUST  PREVENTIVE. 

The  following  is  a  good  rust  preventive  for  steel: 
16  parts  turpentine,  and  1  part  caoutchouc  dissolved 
by  a  gentle  heat.  To  this  add  8  parts  boiled  oil,  stir 
and  at  the  same  time  bring  to  the  boiling  point.  Apply 
with  a  brush  after  the  manner  of  varnishing.  This 
coating  can  be  removed  by  the  use  of  turpentine  if 
desired.  ■ — 

TABLE  OF  COMPOSITION  OF  COMMON  ALLOYS. 


White  Bearing  Metal 2 

Bronze 90 

Bronze  for  bushings 130 

Bearing  Bronze  (for  motors) 110 

Phosphor  Bronze  (for  gears) 90 

Bronze   for   flanges,    etc.,    to    be 

brazed 32 

Babbitt  metal 2 

Brass  for  light  parts 2 


*  Phosphor  tin. 
MELTING  POINTS  OF  VARIOUS  METALS. 


Aluminum 

Bronze 

Cast  Iron  (Cray). 
Cast  Iron  (White) 

Copper 

Lead 

Steel 

Tin 

Wrought  Iron .... 


Degrees  F. 


1,157 
1,692 

2,012  to  2,228 
1,922  to  2,075 
1,929  to  1,996 

608  to  61S 
2,372  to  2,532 

442  to  446 
2,732  to  2,912 


451) 


The  Modern  Gas  Tractor 


ROAD  SIGNS. 

American  Motor  League  "Caution  Signs."  Back- 
ground  and   posts  white,   symbols  black. 

No.  1  indicates  approach  to  a  steep  descent;  No.  2, 
approach  to  a  railroad  crossing;  No.  3,  approach  to 
a  branch  road  (to  right) ;  No.  4,  approach  to  a  branch 
road  (to  left);  No.  5,  approach  to  cross  roads;  No.  6, 
approach  to  a  ditch  or  abrupt  depression  in  the  road; 
No.  7,  approach  to  a  hummock  or  "thank  you,  ma'am;" 
No.  8,  approach  to  a  city,  village  or  other  collection 
of  inhabited  dwellings;  No.  9,  is  a  general  caution 
signal  indicating  the  proximity  of  any  danger  or  obstruc- 
tion not  scheduled  above,  or  any  other  condition  requir- 
ing caution.  No.  9  (not  shown  in  cut)  is  a  plain  white 
sign  and  can  be  improvised  in  emergency  cases  by  using 
a  sheet  of  white  cloth  fastened  upon  a  board  of  proper 
shape.  "Each  sign  is  placed  at  a  distance  of  not  less 
than  200,  nor  more  than  300  yards  from  the  point  to 
which   it   refers. 


Fig.  203. — Road  Signs  of  American  Motor  League  That  Give 
Warnings  of  Interest  to  Tractor  Operators  or  Motorists. 


The  Modern  (Jas  Tractor  431 

TABLE  OF  HORSE=PO\VER  COSTS. 


I  Rate  of  Fuel 
Motive  Power     Consumption. 


Gas  Engine  on   In  pounds  per 


Producer  Gas. 


HP.  Hour. 


Cost  of  Fuel  per  Brake  Test  Horse-power 


1   Hour. 


Cost  of  Coal  per  2.000  Pounds. 


1.00 
1.25 
1.50 


S3 .  00 

84.00 

$5.00 

.0012 
.0015 
.0019 
.0023 

.0016 
.0020 
.  0025 
.0030 

.0020 
.0025 
.0031 
.0037 

$6  .00   $7 .  00 


.0024  !  .0028 

. 0030  . 0035 

.0037  .0044 

.0044  .0053 


Gas  Engine  on 
Natural  Gas. 


In  Cubic  Feet 
per  H.P.  Hour 


9 
10 
I  1 
12 


Cost  of  Natural  Gas.  1,000  Cubic  Feet. 


$0.15 


.0014 
.0015 
.0017 
0018 


SO .  20 


.0018 
.0020 
.0022 
.0024 


$0.25 


.0023 
.0025 
.0028 
.0030 


$0.30 


.0027 
.0030 
.0033 
.0036 


Gas  Engine  on 

Illuminating 

Gas 

In  Cubic  Feet 
per  H.P.  Hour. 

Cost  of  Gas 

per  1,000  Cubic  Feet. 

$0.60 

SO.  70 

$0 .  80 

$0 .  90 

$1.00 

15 

17 
20 

.0090 
.0102 
.0120 

.0105 
.0119 
.0140 

.0120 
.0136 
.0160 

.0135        .0150 
.0153        .0170 
.0180       .0200 

Gasoline  Engine 

In  Pints  per 

Brake 
H.P.  Hour. 

Cost  of  Gasol|ne  per  Gallon. 

SO.  10 

$0.  12 

$0.  14 

$0.16 

$0.18 

0.80 
1.00 
1.10 

.0100 
.0125 
.0137 

.0120 
.0150 
.0165 

.0140 
.0175 
.0192 

.0160 
.0200 
.0220 

.0180 
.0247 

Table  concluded  on  next  page. 


4.">2  The  Modern  (Jas  Tractor 

TABLE  OF  HORSE=POWER  COSTS===Continued. 


Electric  Motor 
85%    Efficiency 

In  Kilowatts 
per  H.P.  Hour 

Cost  of  Electricity  per  Kilowatt  Hour. 

of  Wiring. 

$0 .  02 

$0 .  03   SO .  04   SO .  05 

■SO .  07 

0.878 

.0175 

.0263  1   0351   .0439 

1 

.0614 

Steam  Engine 
on  Coal. 

In  Pounds 
per  H.P.  Hour. 

Cost  of  Coal  per  2,000  Pounds. 

$3 .  00 

$4.00 

$5 .  00 

$6 .  00 

$7 .  00 

4 
6 

8 
10 

.0060 
.0090 
.0120 
.0150 

.0080 
.0120 
.0160 
.0200 

.0100 
.0150 
.0200 
.0250 

.0120 
.0180 
.0240 
.0300 

.0140 
.0210 
.0280 
.  0350 

CAPACITY  OF  CYLINDERS. 

NUMBER  OF  GALLONS  FOR  ONE  FOOT  DEPTH. 

When  diameter  is  given  in  feet        =  (square  of  diameter)x5.873 

When  diameter  is  given  in  inches    =  (square  of  diameter)x0.0408 

TABLE  OF  CAPACITIES  OF  CYLINDRICAL  TANKS  IN  LIQUID 

GALLONS    (APPROXIMATE). 


Gals. 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

Gallons 

per 
inch 

6x12 

6x18 

6x24 

6x36 

6x42 

6"  dia. 

.  122 

7x12 

7x18 

7x24 

7x30 

7x36 

7x42 

7x48 

7"  " 

.165 

8x15 

8x18 

8x24 

8x30 

8x36 

8x42 

8x45 

8x48 

8"  " 

.217 

9x12 

9x15 

9x18 

9x24 

9x30 

9x34 

9x36 

9x40 

9"   ' 

.275 

10x20 

10x24 

10x26 

10x28 

10x32 

10"  " 

.340 

12x16 

12x18 

12x20 

12x24 

12"  " 

.486 

Gals 

10 

15 

20    25 

30 

35 

40 

45 

50 

Gallons 

per 

inch 

10x32 

10x48 

10"  dia. 

.340 

12x24 

12x34 

12x42 

12x50 

12x60 

12"  " 

.486 

14x18 

14x24 

14x30 

14x38 

14x44 

14x52 

14x60 

14"  " 

.666 

1  fix  is 

16x24 

16x30 

16x36 

16x42 

16x48 

16x54 

16x60 

16"  " 

.870 

The  Modern  (Jas  Tractok 


4..:; 


RULE  FOR  CAPACITY  OF  SQUARE  OR  RECT= 
ANGULAR  TANKS. 

Multiply  height  in  inches  by  width  in  inches  and  the 
product  by  length  in  inches,  then  divide  by  231,  which 
will  give  answer  in  gallons.  For  small  tanks,  divide 
by  57.75,  and  you  will  obtain  capacity  in  quarts. 

TRACTIVE  EFFORT  ON  VARIOUS  SURFACES. 

Pounds  per  Ton. 

On  rails  or  plates 5 .  16 

Asphalt  or  hardwood 12 .  24 

Macadam 30 .  60 

Loose  gravel 140  to  200 

Sand 400 . 


REVOLUTIONS  OF  WHEELS   OF   VARYING 
DIAMETER  PER  MILE. 


Dia. 

Circum. 

in 

in 

Inches. 

Feet. 

„        ,     .  For  R.P.M. 

Revolutions  multiply 

per  Miles  per 

Mlle-  Hour  by 


For  R.P.S. 

multiply 
Miles  per 
Hour  by 


48 

12.57 

420.0 

7.00 

0.1166 

50 

13.00 

403.4 

6.72 

0.1120 

52 

13.61 

387.9 

6.46 

0.1073 

54 

14.14 

373.4 

6.22 

0 . 1033 

56 

14.66 

360.2 

6.00 

0 . 1000 

58 

15 .  18 

347.8 

5.79 

0.0965 

60 

15.71 

336.1 

5.60 

0.0933 

62 

16.23 

325.3 

5.42 

0.0903 

64 

16.75 

315.2 

5.25 

0.0875 

66 

17.28 

305.5 

5.09 

0.0848 

68 

17.80 

296 .  C) 

4.94 

0.0823 

70 

18.36 

288.1 

4.80 

0.0798 

72 

18.85 

280.1 

4.67 

0.0778 

78 

20.42 

258.6 

4.31 

0.0718 

84 

21.99 

240.1 

4.00 

0.0666 

90 

23.56 

224.1 

3.73 

0.0622 

96 

25.16 

210.1 

3.50 

0.0586 

454 


The  Modern  Gas  Tractor 


STRENGTH  OF  AUTOMOBILE  STEELS. 

SUMMARY     OF    TENSILE     TESTS 

Made    with  2-inch   Test  Specimens   of  Carpenter  Steel  Company's 

Auto  Steels  in  Accordance   with  the  Standard  Specifications 

of   the   American   Society    for   Testing   Materials. 


Grade 

"On 

.-.  ,r.  a 
.2  §8 

Z'-r.C 

0  0 
5  c 

OJhH 

0 

e 

Condition. 

43  O  c3 

2,  o& 

g>0 

3« 

% 

% 

Chrome-Nickel  Auto-Steel  No.  5-317 

65,650 

91,200 

27.0 

64.3 

Natural 

" 

210.000 

315.000 

5.0 

19.0 

Tempered 

" 

185,400 

269,200 

6.0 

20.2 

" 

" 

140,000 

225,200 

8.0 

30.2 

" 

" 

" 

114,000 

130,500 

19.0 

60.0 

Toughened 

Chrome-Nickel  Auto- 

Steel  No.  3-317 

70.000 

106,000  18.0 

45.0 

Natural 

135,000 

197,000]   9.0 

37.0 

Tempered 

" 

90,000 

110,000  25.0 

55.0 

Toughened 

Dynamic  Auto-Steel 

No.  L3-14 

103,800 

121,39020.0 

60.0 

Special  Nickel  Steel 

No.  575 

80,000 

99,000  21.0 

58.2 

" 

" 

No.  575 

87,000 

102,000  21.0 

62.0 

Crucible  Auto-Steel 

No.  L-521 

160,000 

175,000]   7.0 

30.0 

Tempered 

Special  Auto-Steel 

No.  506 

70,000 

113,950  22.0 

49.0 

Natural 

No.  506 

71,200 

105,600  24.0 

49.3 

" 

Weldable  Auto-Steel 

No.  492 

49,050 

93.000  21.5 

35.0 

" 

" 

No.  492 

50,000 

93,000  22.0 

37.0 

Auto-Steel 

No.  478 

48,300 

74,500  29.0 

43.0 

No.  478 

46,500 

77,500  28.0 

1 

45.0 

No.  5-317.  Suitable  for  transmission  gears,  counter-shafts 
and  parts  used  for  transmission  of  power. 

No.  3-317.  Mild-temper  suitable  for  ease  hardened  gears. 

No.  L  3-14.  Axle-steel,  to  withstand  alternating  stresses 
and  dynamic  strains. 

No.  575.  Contains  3  H  per  cent,  nickel  and  is  manufactured 
to  meet  the  U.  S.  Navy  specification  known  as  "High  Grade." 

No.  L-521.  Crucible  gear-steel  (moderate  price)  gears  can 
be  tempered  and  do  not  require  hardening. 

No.  506.  Manganese  steel  for  shafts,  bolts,  etc.,  not  sub- 
jected    to      excessive     alternating     or     recurrent     stresses. 

No.    492.  Special    straight-carbon    crucible    steel,    with    a 


The  Modern  Gas  Tractor 


455 


fairly  high  tensile  strength,  suitable  for  axles  and  other  parts 
that  have  to  be  welded. 

No.  478.  Special  high-grade  open-hearth  steel,  which  is 
particularly  adapted  to  such  parts  as  are  not  subjected  to 
unusual  strains.  It  is  suitable  for  axles,  axle-journals,  and 
various  small  parts  of  automobiles. 


USEFUL  CONVERSION  TABLES  AND  RULES. 


TO  CHANGE  COMMON  FRACTIONS  INTO  A  DECIMAL 

To  convert  a  common  fraction  into  a  decimal :  Divide 
the  numerator  by  the  denominator,  adding  to  the 
numerator  as  many  ciphers  prefixed  by  a  decimal  point 
as  are  necessary  to  give  the  number  of  decimal  places 
desired  in  the  result. 

%  =  2.0000  +  3  =  0.6666  + 


DECIMAL     EQUIVALENTS    OF     FRACTION 
ONE  INCH. 


OF 


ADVANCING     BY    64TH. 


1-64 

0.015625 

17-64 

0 . 265625 

33-64 

0.515625 

49-64 

0.765625 

1-32 

0.03125 

9-32 

0.28125 

17-32 

0.53125 

25-32 

0.78125 

3-64 

0.046875 

19-64 

0 . 296875 

35-64 

0 . 546875 

51-64 

0 . 796875 

1-16 

0.0625 

5-16 

0.3125 

9-16 

0 . 5625 

13-16 

0.8125 

5-64 

0.078125 

21-64 

0.328125 

37-64 

0.578125 

53-64 

0.828125 

3-32 

0.09375 

11-32 

0.34375 

19-32 

0 . 59375 

27-32 

0.84375 

7-64 

0.109375 

23-64 

0.359375 

39-64 

0.609375 

55-64 

0 . 859375 

1-  8 

0.125 

3-  8 

0 .  375 

5-  8 

0.625 

7-  8 

0.875 

9-64 

0.140625 

25-64 

0.390625 

41-04 

0 . 640625 

57-64 

0 . 890625 

5-32 

0.15625 

13-32 

0.40625 

21-32 

0 . 65625 

29-32 

0.90625 

11-64 

0.171875 

27-64 

0.421875 

43-64 

0.671875 

59-64 

0.921875 

3-16 

0.1875 

7-16 

0 . 4375 

11-16 

0.6875 

15-16 

0 . 9375 

13-64 

0.203125 

29-64 

0.453125 

45-64 

0.703125 

61-64 

0.953125 

7-32 

0.21875 

15-32 

0 . 46875 

23-32 

0.71875  ' 

31-32 

1)  '.His;:. 

15-64 

0.234375 

31-64 

0  484375 

47-64 

0.734375 

63-64 

0  9S4375 

1-  4 

q  25 

1-  2 

0.50 

3-  4 

0.75 

1 

1. 

4r><; 


Thk  Modern  Gas  Tractor 


MONEY  CONVERSION  TABLES. 


English.  U.  S. 

1  Farthing $0.0051 

1  Farthing $0.0051 

1  Penny 0203 

6  Pence 0.1217 

1  Shilling 0.2433 

20  Shillings 4.8665 

1  Pound 4.8665 

5  Pounds 24.3325 


U.  S.  English. 

$0.01 1 . 96  Farthings 

$0.01 1.96  Farthings 

0.01 0.492  Pence 

0.25 12.3 

0.25 1.0275  Shillings 

1.00 4.11 

1.00 0.2055  Pounds 

5.00 1.0275       " 


French.  U.  S. 

1  Centime $0.00193 

10  Centimes 0.0193 

100         "         0.193 

1  Franc 0.193 

10  Francs 1.93 


U.  S.  French. 

$0.01    5 .  1813Centimes 

0.10 51.813 

1.00 5. 1813  Francs 

10.00 51.813       " 


German  U.  S. 

1  Pfennig $0.00238 

25  Pfennigs 0.0595 

100         "         0.238 

1  Mark 0.238 

10  Marks 2 .  38 


U.  S.  German. 

$0.01 4.201    Pfennigs 

0.25 1.05025   Marks 

1.00 4.201 

10.00 42.01 


THERMOMETER  SCALE  CONVERSIONS. 

One  Fahrenheit  degree   =    5-9  degree  Centigrade   =   4-9 
degree  Reaumur.     In  the  following  conversion  formulae: 

F  =  Degrees  Fahrenheit. 
C  =  Degrees  Centigrade. 
R  =  Degrees  Reaumur. 

Readings  above  freezing  point,  32  degrees  F.,  zero  C,  zero 
R.,  are  positive  (  +),  readings  below  are  treated  as  negative  ( — ). 


F  =  —  +  32;  F  =  ^  +  32;  C  = 


R  = 


4(F  — 32) 


Freezing  point  F  =  32  degrees  =  zero  C  =  zero  R. 
Boiling  point  =  212  degrees  F  =  100  degrees  C  =  80  degrees  R. 


The  Modern  <Ias  Tractor  457 

METRIC  CONVERSION  TABLES. 

U.  S.  TO  METRIC.  METRIC  TO  U.  S. 


1  inch  =  25.4001  millimeters.  1  meter  =  39.3700  inches. 

1  foot  =  0.304801  meters.  1  meter  =  3.28083  feet. 

1  yard  =  0.914402  meters.  1  meter  =  1.09361  yards. 

1  mile  =  1.60935  kilometers.  1  kilometer  =  0.62137  miles. 


SQUARE. 


1  square  inch  =  6.452  square  centimeters. 
1  square  foot  =  9.290  square  decimeters. 
1  square  yard  =  0.836  square  meters. 
1  square  centimeter  =  0.1550  square  inchi 
1  square  meter  =  10.7640  square  feet. 
1  square  meter  =  1.196  square  yards. 


1  cubic  inch  =  16.387  cubic  centimeters. 

1  cubic  foot  =  0.02832  cubic  meters. 

1  cubic  yard  =  0.765  cubic  meters. 

1  cubic  centimeter  =  0.0610  cubic  inches. 

1  cubic  meter  =  35.314  cubic  feet. 

1  cubic  meter  =  1.308  cubic  yards. 


1  grain  =  64.7989  milligrammes. 

1  avoirdupois  ounce  =  28.3495  grammes. 

1  troy  ounce  =  31.10348  grammes. 

1  avoirdupois  pound  =  0.45359  kilogrammes. 

1  milligramme  =  0.01543  grains. 

1  kilogramme  =  15432.36  grains. 

1  hectogramme  =  3.5274  avoirdupois  ounces. 

1  kilogramme  =  2.20462  avoirdupois  pounds. 


458 


The  Modern  Gas  Tractor 


METRIC  CONVERSION  TABLES===Continued. 

CAPACITY. 

1  fluid  drachm  =  3.70  cubic  centimeters. 

1  fluid  ounce  =  29.57  milliliters. 

1  quart  =  0.94636  liters. 

1  gallon  =  3.78544  liters. 

1  milliliter  =  0.27  fluid  drachms. 

1  centiliter  =  0.338  fluid  ounces. 

1  liter  =  1.0567  quarts. 

1  dekaliter  =  2.6417  gallons. 


USEFUL  INFORMATION. 

HORSE-POWER   OF   SHAFTS   FOR   GIVEN    DIAMETER 
AND  SPEED. 


Diameter 

Revolutions  per  Minute. 

of  Shaft 

Inches. 

| 

100 

125    150 

175 

200 

225 

250 

300    350 

400 

l»/ie 

2.4 

3.0 

3.6 

4.2 

4.8 

5.4 

6.0 

7.2 

8.4 

9.6 

r/ie 

4.3 

5.4 

6.5 

7.6 

8.6 

9.8 

10.8 

13.0 

15.2 

17.2 

l"/l6 

6.5 

8.0 

9.7 

11.2 

13.014.6 

16.0 

19.4 

22.4 

26.0 

l16/l6 

10.012.5 

15.0 

17.5 

20.0  22.5 

25.0 

30.0 

35.0 

40.0 

2VlG 

14.017.8 

21.0 

24.5 

28.031.5 

35.6 

42.0 

49.0 

56.0 

RULES  FOR  DETERMINING  THE  SPEED  OF  PULLEYS. 

1.  To  find  the  number  of  revolutions  of  the  driven 
shaft  when  the  diameter  of  the  driving  pulley  and  its 
speed  are  given,  multiply  the  diameter  of  the  driving 
pulley  by  its  number  of  revolutions  per  minute,  and 
divide  the  product  by  the  diameter  of  the  driven  pulley; 
the  quotient  will  be  the  speed  of  the  driven  pulley  ex- 
pressed in  revolutions  per  minute. 


The  Modern  Gas  Tractor  459 

Example:  Driving  pulley  is  24  inches  in  diameter  and 

makes  125  revolutions  per  minute.    At  what  rate  would 

a  pulley  8  inches  in  diameter  be  driven? 

24X125  ,    . 

—  =  37o  revolutions  per  minute. 
8 

2.  To  find  the  diameter  of  the  driven  pulley  when 
the  diameter  and  number  of  revolutions  of  the  driving 
pulley  are  given,  multiply  the  diameter  of  the  driving 
pulley  by  the  number  of  its  revolutions,  and  divide  the 
product  by  the  number  of  revolutions  the  driven  pulley 
is  to  make. 

Example:  What  would  be  the  diameter  of  the  driven 
pulley  making  375  revolutions  per  minute,  if  the  driving 
pulley  is  24  inches  in  diameter  and  makes  125  revolu- 
tions per  minute? 

24X125      o.     , 

-  =  8  inches  in  diameter. 
375 

3.  To  find  the  number  of  revolutions  of  the  driving 

pulley  when  its  diameter  and  the  diameter  and  speed 

of  the  driven  pulley  are  given,  multiply  the  diameter 

of  the  driven  pulley  by  its  revolutions  and  divide  the 

product   by   the  diameter  of  the  driving  pulley;     the 

quotient  will  be  the  speed  of  the  driving  pulley  expressed 

in  revolutions  per  minute.     Example: 

8X375      ine 

=  125  revolutions  per  minute. 

24 

4    To  find  the  diameter  of  the  driving  pulley,  multiply 

the  diameter  of  the  driven  pulley  by  the  number  of 

its  revolutions  per  minute,  and  divide  the  product  by 

the  number  of  revolutions  of  driving  shaft ;   the  quotient 

will   be  the  diameter   of   the   driving  pulley  required. 

Example: 

8X375  .  . 

=  24  inches  in  diameter. 

125 


460 


The  Modern  (J as  Tractor 


HORSE-POWER  BELTING  WILL  TRANSMIT. 


Width  of 

Horse-power  per  100  Feet  Belt-Speed. 

Belt, 

Inches. 

Single  Belt. 

Double  Belt. 

1 

0.09 

0.18 

2 

0.18 

0.36 

3 

0.27 

0.55 

4 

0.36 

0.73 

5 

0.4.5 

0.91 

6 

0.55 

1.09 

7 

0.64 

1.27 

8 

0.73 

1.46 

9 

0.82 

1.64 

10 

0.91 

1.82 

11 

1.00 

2.00 

12 

1.09 

2.18 

14 

1.27 

2.55 

16 

1 .  4r, 

2.91 

18 

1.64 

3.27 

20 

1.82 

3.64 

22 

2.00 

4.00 

24 

2.18 

4.36 

28 

2.55 

5.09 

32 

2.91 

5.82 

36 

3.27 

6.55 

40 

3.64 

7.27 

The  Modern  Gas  Tractor 


-Mil 


Fig.  204. —  Belt  Driven  Centrifugal  Pump  Suitable  for  Irriga- 
tion Purposes  May  be  Driven  by  Direct  Connection  With 
Belt  Pulley  of  Gas  Tractor  Power  Plant. 


CAPACITY  OF  CENTRIFUGAL  PUMPS  AXD  POWER 
NEEDED  TO  OPERATE. 


Capacity 

H.  P. 

Diam.  of 

Diam.  of 

Weight, 

per    Minute 

Required, 

Suction 

Discharge 

Gallon-. 

Foot  Lift. 

Pipe  in  Ins. 

Pipe  in  Ins. 

Pounds. 

75-80 

0.032 

2 

IX 

70 

80-125 

0.04 

2 

2 

120 

125-160 

0 .  05 

2H 

2 

190 

160-250 

0.085 

3 

2y2 

230 

250-350 

0 .  126 

4 

3 

250 

350-400 

0.190 

5 

ZV2 

375 

400-600 

0.270 

5 

4 

450 

600-900 

0.420 

6 

"> 

500 

900-1,800 

0.525 

8 

6 

750 

1,800-3,000 

1 .  35 

10 

8 

1,200 

::.000-4,000 

1.80 

12 

10 

L.725 

4,000-5,000 

2  40 

14 

12 

2,200 

4»;l> 


The  Modern  Gas  Tractor 


WHAT  MAY  BE  ACCOMPLISHED  BY  PUMPS  OF  VARY 
ING  CAPACITY  IN  IRRIGATION  WORK. 

Acres  Irrigated  in  10  Hours. 


Gallons  Pumped 

1-in. 

2-in. 

3-in. 

4-in. 

5-in. 

6-in. 

per  Minute. 

deep. 

deep. 

deep. 

deep. 

deep. 

deep. 

600 

13.2 

6.6 

4.4 

3.3 

2.6 

2.2 

824 

18.2 

9.1 

6.0 

4.5 

3.6 

3.0 

944 

20.8 

10.4 

6.9 

5.2 

4.1 

3.4 

988 

21.8 

10.9 

7.2 

5.4 

4.3 

3.6 

1,000 

22.1 

11.0 

7.3 

5.5 

4.4 

3.7 

1,200 

26.5 

13.2 

8.8 

6.6 

6.3 

4.4 

1,500 

33.1 

16.5 

11.0 

8.2 

6.6 

5.5 

2,000 

44.2 

22.1 

14.7 

11.0 

8.8 

7.3 

Acres  Irrigated  in  24  Hours. 


Gallons  Pumped 

1-in. 

2-in. 

3-in. 

4-in. 

5-in. 

6-in. 

per  Minute. 

deep. 

deep. 

deep. 

deep. 

deep. 

deep. 

600 

31.8 

15.9 

10.6 

7.9 

6.3 

5.3 

824 

43.7 

21.8 

14.5 

10.9 

8.7 

7.3 

944 

50.0 

25.0 

16.7 

12.5 

10.0 

8.3 

988 

52.4 

26.2 

17.4 

13.1 

10.4 

8.7 

1,000 

53.0 

26.5 

17.6 

13.2 

10.6 

8.8 

1,200 

63.6 

31.8 

21.2 

15.9 

12.7 

10.6 

1,500 

79.5 

39.7 

26.5 

19.9 

15.9 

13.2 

2,000 

106.0 

53.0 

35.3 

20.5 

21.2 

17.6 

INDEX 


Aekerman  Axle,  Parts  of,  311. 

Ackerman  Front  Axle,  Con- 
struction of,  311. 

Action  of  Automatic  Carbure- 
tors, 167 

Action  of  Change  Speed  Gear, 
267. 

Action  of  Clutch  Described, 
248. 

Action  of  Float  Feed  Carbu- 
retor, 164. 

Action  of  Friction  Roll  Clut- 
ches, 256. 

Action  of  Gas  Motors,  101. 

Action  of  Kerosene  Vaporizer, 
177. 

Action  of  Magneto  Ignition 
Systems,  214. 

Action  of  Self-Lift  Gang 
Plough,  403. 

Action  of  Simple  Mixing  Valve, 
161. 

Action  of  Valves,  129. 

Actual  Power  of  Horse,  41. 

Advantages  of  Concentric 
Float,  168. 

Advantages  of  Large  Wheels, 
294. 

Advantages  of  One  Cylinder 
Motors,  110. 

Advantages  of  Power  Trac- 
tion, 37. 


Adjusting   Bearings,    How   to. 

384. 
Adjustment  of  Brakes,  399. 
Advice  on  Tractor  Operation, 

341. 
Agriculture,     Application     of 

Mechanical  Power,  35. 
Air,  Composition  of,  160 
Air  Valves,  Auxiliary,  171. 
Air,  Weight  of,  161. 
Alcohol,  Facts  About,  158. 
Analysis    of    Requirements    of 

Tractor,  53. 
Animals    Used    in    Ploughing, 

35, 
Anti-freezing  Solutions,  445. 
Automatic  Carburetors,   167. 
Automatic    Steering    Arrange- 
ment, 314. 
Automobile     Steels,     Strength 

of,  454. 
Automobile        Type        Power 

Plants,  125. 
Auto  -  Tractor     Attachment. 

428. 
Auto      Tractor      Attachment, 

Capacity  of,  433. 
Auxiliary  Air  Valves,  171. 
Auxiliary     Engine     to     Start 

Power  Plant,  332. 
Axle,  Ackerman,  311. 
Axle,  One  Piece  Front,  308. 
Axle,  Worm  Drive  for  Tractor, 

325. 


463 


464 


Index 


B 


Balance  of  Two  Cylinder 
Motors,  119. 

Battery  Ignition  Methods,  209. 

Bearings,  Fitting,  388. 

Bearings,  How  to  Scrape,  388. 

Baume  Test,  Method  of  Mak- 
ing, 158. 

Belt  Operated  Machines, 
Power  Needed  for,  423. 

Blacksmith  Tools  for  Farm 
Use,  362. 

Block  Type  Clutches,  254. 

Brake  Horse-power,  Calculat- 
ing, 444. 

Brake  Test,  Meaning  of,  94. 

Brake  Test,  Method  of  Mak- 
ing, 94. 

Brakes,  Adjustment  of,  399. 

Breaking,  Cost  of  Tractor 
Power,  48. 


C 


Cam  Shaft  Drives,  139. 

Capacity  of  Auto  Tractor  At- 
tachment, 433. 

Capacity  of  Centrifugal  Pumps 
461. 

Capacity  of  Cylinders,  452. 

Carbon  Deposits,  How  to 
Reduce,  376. 

Carbon  Deposits,  Symptoms 
Denoting,  375. 

Carbon  Deposits,  Troubles 
Due  to,  375. 

Carburetion,  Causes  of  De- 
fective, 389. 

Carburetion,  Elements  of,  160. 

Carburetor  Air  Valves,  171. 


Carburetor,  Concentric  Float 
Type,  168. 

Carburetor  Float  Construc- 
tion, 171. 

v  arburetor  Spray  Nozzles,  169. 

Carburetors,  Advantage  of 
Float  Feed,  165. 

Carburetors,  Automatic,  Ac- 
tion of,  167. 

Carburetors,  Parts  of,  168. 

Care  of  Piston,  383. 

Care  of  Piston  Rings.,  383. 

Caterpillar  Tread,  Action  of, 
304. 

Caterpillar  Tread  Tractors, 
88. 

Cause  of  Poor  Compression, 
373. 

Causes  of  Mixture  Troubles, 
389. 

Causes  of  Noisy  Operation, 
384. 

Centrifugal  Governors,  329. 

Centrifugal  Pump  Construc- 
tion, 226. 

Centrifugal  Pump,  Power 
Needed  to  Operate,  461. 

Chains,  Defects  of  Driving, 
397. 

Change  Speed  Gearing,  I.  H. 
C,  276. 

Change  Speed  Gearing.  Morris, 
270. 

Clutch,  Action  of  Simple 
Type  Described,  248. 

Clutch,  Holt  Tractor,  250. 

Clutch,  Three  Plate,  250. 

Clutch,  Troubles  of,  393. 

Clutch,  Why  Needed,  245. 

Clutches,  B-ioek  Type,  254. 

Clutches,  Friction  Disc,  254. 


Index 


465 


Clutches,  Friction  Roll,  256. 
Clutches,     Requirements    of, 

248. 
Clutches,  Typical  Tractor,  250. 
Coil  Vibrator,  Action  of,  194. 
Combined    Farm    Truck    and 

Tractor,  91. 
Combined    Gas    Tractor    and 

Road  Roller,  420. 
Comparing     Two     and     Four 

Stroke  Motors,  99. 
Comparing     Work     of     Horse 

and  Tractor,  39. 
Composition  of   Common    Al- 
loys, 449. 
Compression,    Cause   of   Poor, 

373. 
Compression  of  Gas,  Value  of, 

105. 
Concentric    Float    Carburetor. 

Advantages,  168. 
Connecting      Rod      Bushings, 

How  to  Replace,  386. 
Connecting   Rod   Design,   142. 
Connecting  Rod  Types,  142. 
Constant  Level  Splash  System. 

242. 
Construction      of      Ackerman 

Axle,  311. 
Construction     of     Centrifugal 

Pump,  226. 
Construction  of  Cylinders,  139. 
( Jonstruction  of  Induction  Coil, 

193. 
Construction        of         Tractor 

Frames,  282. 
Construction  of  Wheels,   294. 
Conventional    Drive    Gearing. 

318. 
Cooling  Fan,  Action  of,  227. 
Cooling  Fan  Drive,  227. 


Cooling  System  Faults,  394. 
Cooling    System    Forced    Cir- 
culation, 222. 
Cooling       System,        Thermo 

Syphon,  222. 
Cooling  Systems,  Oil,  224. 
Cooling  Systems,  Pump  Types, 

225. 
Cost    of    Tractor     Ploughing, 

47. 
Cost     of     Tractor     Power     in 

Various  Work,  51. 
Crankcase,     Design     of     Four 

Cylinder,  152. 
Crankcase,     Single     Cylinder, 

150. 
Crankshaft  Design,   144. 
Crankshafts,     Four     Cylinder, 

146. 
Crankshaft,  One  Cylinder,  145. 
Crankshaft,      Two      Cylinder. 

145. 
Current  Production.   Methods 

of,  189. 
Cylinder  Construction,  139. 
Cylinder  Design,  133. 
Cylinder   With   Detachable 

Head,  133. 
Cylinders,    How    to    Remove, 

371. 


I) 


Decimal     Equivalents     Table, 

455. 
Deep     Ploughing,     Value     of, 

77. 
Defective  Carburetion,  Causes 

of,  389. 
Defects    of     Driving     Chains, 

397. 


466 


Index 


Design  of  Connecting  Rods, 
142. 

Design  of  Crankshafts,  144. 

Design  of  Cylinders,  133. 

Design  of  Float  Chambers, 
170. 

Design  of  Pistons,  140. 

Detachable  Head  Cylinder, 
133. 

Diagram  of  Four  Cylinder 
Ignition  System,  212. 

Differential,  Bevel  Pinion,  280. 

Differential  Gear  Action,  278. 

Differential  Gear  Lock,  Utility 
of,  281. 

Differential  Gear,  Why  Used, 
276. 

Differential  Pinions,  Action  of, 
279. 

Disadvantages  of  Steam  Trac- 
tors, 58. 

Distinctive  Designs  of  Trac- 
tors, 87. 

Draft  for  Wagons,  Table  of, 
71. 

Draft,  Meaning  of,  42. 

Draft  of  Tractors,  57. 

Draft  of  Wagons,  71. 

Draft,  Traction  Dynamometer 
for  Measuring,  96. 

Drawbar  Pull,  How  Deter- 
mined, 96. 

Dry  Batteries,  Action  of,  189. 

Dry  Battery,  Capacity  of,  190. 


K 


Economical   Aspect   of   Power 

Traction,  44. 
Efficiency  of  Steam  and   Gas 

Power,  56. 


Efficiency,  Thermal,  of  Horse, 

40. 
Electrical  Ignition,  Advantages 

of,  188. 
Electric  Spark,  How  Produced 

in  Cylinders,  196. 
Elements  in  Carburetion,  160. 
Elements   of   Tractor   Design, 

61. 
Engine  Base  Design,  149. 
Extension    Rims,    Why    Used, 

302. 

F 

Fall  Ploughing,  Value  of,  45. 

Faults  in  Running  Gear,  396. 

Faults  of  Cooling  Systems,  394. 

Faults  of  Ignition  Systems, 
391. 

Faults  of  Oiling  Systems,  394. 

First  Steam  Ploughing  Engine, 
37. 

First  User  of  Ploughs,  37. 

Fitting  Bearings,  388. 

Float  Chamber  Design,  170. 

Float    Construction,    171. 

Float  Feed  Carburetors,    165. 

Float  Feed  Carburetor,  Action 
of,  166. 

Flywheel  Construction,  146. 

Flywheel  Marks,  Relation  to 
Valve  Timing,  382. 

Flywheel  Retention,   148. 

Flywheels,  Safe  Speed  of,  148. 

Flywheels,  Weight  of,  147. 

Flywheel,  Utility  of,  146. 

Forced  Circulation  Cooling 
System,  222. 

Formulae  for  Horse-power,  443. 

Formula  for  Indicated  Horse- 
power, 440. 


Index 


46: 


Four-Cycle  Engines,  Operation 

of,  99. 
Four  Cylinder  Ignition  System, 

213. 

Frames,  Cast,  285. 

Frames,  Materials  of  Con- 
struction, 283. 

Frames,  Tractor,  282. 

Frames,  Typical  Tractor,  2s;;. 

Frames,  Use  of  Springs,  291. 

Friction  Disc  Clutch,  254. 

Friction  Roll  Clutches,  256. 

Front  Axles,  Tractor,  308. 

Front  Wheel  Drive,  320. 

Fuel  Injection  System,  181. 

Fuel  Storage  Methods,  354. 

Functions  of  Induction  Coil, 
193. 

Future  Possibilities  of  Gas 
Tractor,  433. 


G 


Gang  Plough,  Self-Lift,  403. 

Gang  Ploughs  for  Tractor  Use, 
401. 

Gang  Ploughs,  Types  of,  401. 

Gas  Motor,  Medium  and 
Heavy  Duty,  113. 

Gas  Motors,  Action  of,  101. 

Gas  Motors,  Automobile  Type, 
125. 

Gas  Motors,  How  Gas  is 
Exploded,  187. 

Gas  Motors,  Multiple  Cy- 
linder Types,    113. 

Gas  Motors,  One  Cylinder, 
110. 

Gas  Motors,  Reason  for  Cool- 
ing, 219. 

Gas  Motors,  Speed,  of,  62. 


Gas    Motors,     Two     Cylinder 
Types,  119. 

Gas  Motors,  Types  of,  07. 

Gas  Motors,  Valve  System  of, 
136. 

Gas  Motors,  Vertical  Cylinder. 
Advantages,  117. 

Gas  Motors,  Why  Oiled,  231. 

Gasoline,     Amount     Used     in 
Threshing,  51. 

Gasoline,    Chemical   Composi- 
tion of,  160. 

Gasoline,  Facts  About,  154. 

Gasoline  Storage  Outfit,  Home 
Made,  357. 

Gas  Power,  Efficiency  of,   56. 

Gas  Power  Plant  Group,   62. 

Gas      Tractor,      Future      Pos- 
sibilities of,  433. 

Gas  Tractor,  Power  Delivery 
by  Belt,  68. 

Gas     Tractor,     Thermal     Ef- 
ficiency of,  56. 

Gas  Tractor,  Weight  Distribu- 
tion, 68. 

Gas    Tractors,    Home    Made, 
425. 

Gas  Tractors,  Sizes  of,  59. 

Gas  Tractors,  Types  of,  74. 

Gas    Tractors,     Why    Most 
Popular,  57. 

Gear  Ratios  for  Various  Work, 
342. 

Gearing,  Troubles  With,  397. 

Gearing,  Worm  Drive,  32."). 

Gears,  Action  of  Change  Speed, 
267. 

Gears,  Construction  of  Drive, 
318. 

Gears,    Differential,   276. 

Gears,    Reversing,    263. 


468 


Index 


Gears,   Speed   Changing,   266. 

Gears,  Wheel  Driving,  Attach- 
ment of,  296. 

Governors,  Construction  of 
Centrifugal,  330. 

Governors,  Engine  Speed,  329. 

Grades,  Influence  on  Traction, 
70. 

Grades,  Power  Needed  to 
Overcome,  70. 

Gradients,  Table  of,  74. 

Grouters,   Types  of,   300. 

Grouters,  Why  Used,  300. 


H 


Hauling,  Power  Needed  for, 
65. 

Hauling,  Power  Needed  for 
Wagons,  71. 

Heavy  Duty  Engines,    113. 

Heider  Friction  Disc  Clutch, 
254. 

High  Tension  Ignition,  Four 
Cylinder  System,  212. 

High  Tension  Magneto,  205. 

High  Tension  Magneto,  Ac- 
tion of,  207. 

High  Tension  Magneto,  Dis- 
tributor Arrangement,   206. 

High  Tension  Magneto,  Speed 
of  Rotation,  206. 

High  Tension  Magneto 
Troubles,  393. 

High  Tension  Spark  Plug,  197. 

Hitches  for  Gas  Tractors,  401. 

Hitch  for  Road  Scrapers,  414. 

Hitch,  Harrow,  416. 

Hitch,  Simple  Drill,  411. 

Home  Made  Gasoline  Storage 
Outfit,  357. 


Home  Made  Gas  Tractors,  425. 

Horse,  Actual  Power  of,  41. 

Horse,  Compared  With  Work 
of  Tractor,  39. 

Horse,  Draft  of,  42. 

Horse  Equivalent  Power  Rat- 
ing of  Tractor,  97. 

Horse-power  Belts  Will  Trans- 
mit, 460. 

Horse-power  Formulae,  443. 

Horse-power  of  Shafts,  458. 

Horse-power,  Rules  for  Cal- 
culating, 439. 

Horse-power,  S.  A.  E.  Formulae 
for,  440. 

Horse-power  Table,  441. 

Horse-power,  Table  of  Costs, 
451. 

Horse,  Thermal  Efficiency  of, 
40. 

Housing  the  Tractor,  343. 

How  Gas  Is  Supplied  Cylinder, 
103. 

How  to  Start  Engines,  326. 

How  to  Adjust  Bearings,  384. 

How  to  Adjust  Main  Bearings, 
385. 

How  to  Ascertain  Grade,  447. 

How  to  Remove  Cylinders, 
371. 

How  to  Remove  Rust,  448. 

Hub  Construction  for  Tractor 
Wheels,  300. 


I 


Igniter  Plate  Construction, 
195. 

Ignition    System    Faults,    391. 

Indicated  Horse-power  De- 
fined, 92. 


Index 


4(H) 


Indicated  Horse-power,  For- 
mula for,  440. 

Induction  Coil,  Construction 
of,  193. 

Induction  Coil,  Functions  of, 
193. 

Influence  of  Grades  on  Trac- 
tion, 70. 

Influence  of  Mechanical  Power 
on  the  Arts,  33. 

Influence  of  Road  or  Field 
Surface  on   Traction,    71. 

Influence  of  Weight  on  Trac- 
tion, 69. 

Inspection  of  Mechanism, 
Value  of,  368. 

Irrigation  Tables,  462. 

K 

Kerosene    Carburetor,    Action 

of,   179. 
Kerosene,  Facts  About,  156. 
Kerosene     Vaporizer,     Action 

of,    177. 

L 

Large  Capacity   Tractors,  82. 
Large  Wheels,  Advantages  of, 

294. 
Liquid   Fuels,   Advantages  of, 

153. 
Liquid  Fuels,  Alcohol,   158. 
Liquid  Fuels,  Gasoline,  154. 
Liquid    Fuels,    Kerosene,    156. 
Live  Axle  Forms  for  Tractor 

Use,  322. 
Location   of   Traction    Engine 

Troubles,  366. 
Location     of     Tractor     Power 

Plants,  370. 


Lock  for  Differential  Gear,  281. 
Loss  of  Power,  Causes  of,  369. 
Low    Tension     Igniter    Plate, 

195. 
Low  Tension  Ignition  System, 

Action  of,  208. 
Low  Tension  Magneto 

Troubles,  393. 
Lubricants,    Requirements   of, 

232. 
Lubricants,   Solid,   234. 
Lubricants,    Supply    to    Main 

Bearings,  244. 
Lubricants,  Why  Used,  232. 
Lubricating  Mediums,   233. 
Lubricating  Systems,  Gravity, 

235. 
Lubrication  by  Splash,  239. 
Lubrication,    Mechanical    Oil- 
ing, 237. 

M 

Main  Bearings,  How  to  Ad- 
just, 385. 

Magneto  Action  Explained, 
200. 

Magneto  Governor,  Action  of, 
203. 

Magneto,  High  Tension  Type, 
205. 

Magneto  Troubles,  High  Ten- 
sion, 393. 

Magneto  Troubles,  Low  Ten- 
sion, 393. 

Magneto  With  Revolving 
Armature,  202. 

Magnetos,  Oscillating  Arma- 
ture Forms,  201. 

Magnetos,  Types  of,  199. 

Mean  Effective  Pressures  of 
Auto  Motors,  440. 


470 


Index 


Mechanical  Generators,  Ad- 
vantages of,  198. 

Mechanical  Oiling  Systems, 
237. 

Mechanical  Power,  Applica- 
tion to  Agriculture,  35. 

Mechanical  Power,  Influence 
on  Arts,  33. 

Medium  Duty  Engines,  113. 

Melting  Point  of  Metals,  449. 

Method  of  Removing  Valves, 
377. 

Method  of  Valve  Grinding, 
377. 

Method  of  Valve  Timing,  3S0. 

Methods  of  Current  Produc- 
tion, 189. 

Methods  of  Exploding  Charge- 
187. 

Methods  of  Final  Drive,  318. 

Methods  of  Fuel  Storage,  354. 

Methods  of  Testing  Batteries, 
392. 

Metric  Conversion  Tables,  457. 

Mixture  Troubles,  Causes  of, 
389. 

Money  Conversion  Tables,  45G. 

Mowers  and  Binders,  Tractor 
Operating,  422. 

Multiple  Cylinder  Motors,  113. 

Multiple  Cylinder  Motors, 
Power  Delivery  of,  112. 

N 

Noisy  Operation,  Causes  of, 
384. 

O 

Ohio  Friction  Roll  Clutch,  256. 
Oil  Cooling  System,  224. 


Oiling  System  Defects,  394. 

One  Cylinder  Motors,  Ad- 
vantages of,  110. 

Operating  Principles  of  Four 
Cycle  Engine,  99. 

Operating  Principle  of  Two 
Cycle  Engine,  106. 

Orchard  Tractors,  75. 


Parts  of  Carburetors,  168. 
Parts  of  Gas  Power  Plant,  62. 
Parts  of  Tractor  Engines,  127. 
Parts     of     Typical     Tractors 

Outlined,  83. 
Petroleum  Products,   156. 
Piston    and    Rings,    Troubles 

With,    383. 
Piston,  Care  of,  383. 
Piston   Design,   140. 
Piston  Rings,  Defects  of,  383. 
Piston  Rings,  Function  of,  141. 
Piston  Rings,  Types  of,  141. 
Piston  Types,  140. 
Plough   Horse,   Pulling  Power 

of,  42. 
Ploughing,  Animals  Used  in,  35. 
Ploughing  by  Tractor,  Cost  of, 

47. 
Ploughing,  Definite  Time  for, 

45. 
Ploughing,    Effect    of   Soil    on 

Power  Needed,  66. 
Ploughing,  First  Engine  for,  37. 
Ploughing,  Power  Needed  for, 

66. 
Ploughing,       Self      Contained 

Tractors  for    82. 
Ploughing,     Test     for     Power 

Needed,   67. 


Index 


471 


Ploughing,  Value  of  Deep,  It. 

Ploughing,  Value  of  Fall,  45. 

Ploughs,  First  Use  of,  37. 

Poor  Compression,  Causes  of, 
373. 

Poor  Compression,  Locating 
Weak  Cylinder,  374. 

Power,  Actual,  of  Horse,  41. 

Power  Delivery  of  Multiple 
Cylinder   Motors,    112. 

Power  Delivery  Under  Belt, 
68. 

Power,  Experiments  of  Watt, 
41. 

Power  for  Ploughing,  Tests  to 
Determine,  67. 

Power  Needed  for  Belt  Oper- 
ated  Machines,   423. 

Power  Needed  for  Hauling. 
65. 

Power  Needed  for  Ploughing, 
66. 

Power  Needed  to  Overcome 
Grades,  70. 

Power  Plant,  Auxiliary  for 
Starting,  332. 

Power  Plant  Group,  What  It 
Is,  62. 

Power  Plant,  How  to  Start. 
326. 

Power  Plant,  Parts  and  Func- 
tions of,  128. 

Power  Plants,  How  Housed, 
370. 

Power  Plants,  Multiple  Cylin- 
der, 113. 

Power  Plants,  Selection  of,  64. 

Power  Plants,  Three  Cylinder, 
121. 

Power  Plants,  Two  Cylinder, 
119. 


Power  Rating  Basi.-  of  Trac- 
tors, 92. 

Power  Rating,  Brake  Horse- 
power, 94. 

Power  Rating,  Drawbar  Horse- 
power, 95. 

Power  Rating,  Horse  Equiv- 
alent, 97. 

Power  Rating,  Indicated 
Horse-power,    92. 

Power  Traction,  Advantages 
of,  37. 

Power  Traction,  Economical 
Aspect  of,  44. 

Practical  Prime  Movers  for 
Tractors,  55. 

Prime  Movers  for  Tractors, 
Practical,  55. 

Prime  Movers,  Steam  and  Gas 
Compared,  55. 

Prime  Movers,  Thermal  Ef- 
ficiency of,  56. 

Producing  Spark  in  Cylinders, 
196. 


R 


Radiator  Construction,  228. 
Radiator,  Functions  of,  228. 
Reason      for      Cooling      Gas 

Engine,  219. 
Replacing      Connecting      Rod 

Bushings,  386. 
Requirements  of  Clutches,  248. 
Requirements       of       Tractor, 

Analysis   of,    53. 
Reversing  Gear.   Holt,   265. 
Reversing  Gear,  Why  Needed, 

262. 
Reversing  Mechanism,  Typical 

263. 


472 


Index 


Revolutions  of  Wheels  Per 
Mile,  453. 

Revolving  Armature  Magneto, 
202. 

Road  Scrapers,  Hitch  for 
Hauling,  414. 

Road  Signs,  Meaning  of,  454. 

Road  Surface,  Influence  on 
Traction,  71. 

Rule  for  Figuring  Tank  Ca- 
pacity, 453. 

Rule  for  Pulley  Speeds,  458. 

Rules  for  Calculating  Horse- 
power, 939. 

Running  Gear  Faults,  396. 

Rust,  How  to  Prevent,  449. 

Rust,  How  to  Remove,  448. 


Scraping  Bearings,  Methods 
of,  388. 

Secor-Higgins  Kerosene  Car- 
buretor, 181. 

Secor-Higgins  Kerosene  Car- 
buretor, Action  of,  186. 

Self-Contained  Tractors  for 
Ploughing,  82. 

Selection  of  Power  Plants,  64. 

Simple  Drill  Hitch,  411. 

Simple  Harrow  Hitch,  416. 

Simple  Mixing  Valve,  Con- 
struction,  161. 

Sizes  of  Gas  Tractors,  59. 

Sizes  of  Tractor  Wheels,  294. 

Sizes  of  Valves,  137. 

Small  Farm  Tractors,  76. 

Soils,  Effect  on  Power  for 
Ploughing,  66. 

Spark  Plug,  High  Tension,  197. 

Spark  Timing,  217. 


Splash        System,        Constant 

Level,  242. 
Speed   Changing   Gear,    Ohio, 

261. 
Speed   Changing   Gears,    Why 

Needed,  266. 
Speed  of  Fly  Wheels,  Safe,  148. 
Speed  of  Magneto  Armatures, 

206. 
Spray  Nozzles  of  Carburetors, 

169. 
Starting  Large  Motor,  Engine 

for,  332. 
Starting    Power    Plant,    Small 

Engine  for,  332. 
Starting  Tractor  Power  Plant, 

326. 
Starting  "Twin  City"  Motor, 

336. 
Steam  Power,  Efficiency  of,  56. 
Steam  Tractors,  Disadvantages 

of,  58. 
Steering,  Automatic,  314. 
Steering      Caterpillar      Tread 

Tractor,  339. 
Steering     Gear,      Chain     and 

Drum,  310. 
Steering      Tractor      by      One 

Wheel,  314. 
Steering    Tractors,    How    Ac- 
complished, 309. 
Storage  Battery,  Construction 

of,  101. 
Strength  of  Automobile  Steels, 

454. 
Suspension  Spoke  Wheel,  290. 


Table    for    Calculating    Brake 
Horse-power,  444. 


Index 


473 


Table  of  Draft  for  Wagons, 
71. 

Table  of  Gradients,  74. 

Table  of  Horse-power,  441. 

Table  of  Horse-power  Costs, 
451. 

Testing  Batteries,  Methods  of, 
392. 

Thermal  Efficiency,  Meaning 
of,  40. 

Thermal  Efficiency  of  Gas 
Tractor,  56. 

Thermal  Efficiency  of  Horse, 
40. 

Thermal  Efficiency  of  Steam 
Tractor,  56. 

Thermometer  Scale  Conver- 
sions, 456. 

Thermo-Syphon  Cooling  Sys- 
tem, 222. 

Three  Cylinder  Power  Plants, 
121. 

Three  Plate  Clutch,  250. 

Three  Point  Support,  How 
Obtained,  288. 

Three  Point  Support,  With 
Swinging  Axle,  290. 

Three  Point  Tractor  Support, 
Why  Used,  287. 

Threshing,  Cost  of  Tractor 
Power,  49. 

Timing  the  Spark,  217. 

To  Change  Common  Fractions 
to  Decimal,  455. 

Tools,  Blacksmithing,  362. 

Tools  for  Care  of  Tractor,  360. 

Tools,  Woodworking,  365. 

Traction  Dynamometer,  Con- 
struction of,  96. 

Traction  Engines,  How  to 
Start,  326. 


Traction  Engines,  Main  Power 
Plant  Troubles,  368. 

Traction      Engine      Troubles, 
Location  of,  366. 

Traction     Gearing,     How     to 
Engage,  337. 

Traction,  Influence  of  Weight 
on,  69. 

Traction  Member,  Caterpillar 
Tread,  304. 

Tractive  Effort  Table,  453. 

Tractor  Attachment  for  Autos, 
428. 

Tractor  Care,  Tools  for,  360. 

Tractor,    Comparing    With 
Work  of  Horse,  39. 

Tractor  Control,   Holt   Cater- 
pillar, 337. 

Tractor  Control  Methods,  334. 

Tractor  Control,  Pioneer  Sys- 
tem, 340. 

Tractor  Control,Twin  City,  3:W. 

Tractor  Control,  Typical  Sys- 
tems, 336. 

Tractor  Designs,  Elements  of, 
61. 

Tractors,    Distinctive    Designs 
of,  87. 

Tractors,  Draft  of,  57. 

Tractor  Drive  by  Chains  and 
Sprockets,  320. 

Tractor   Drive,    Conventional, 
318. 

Tractor   Drive,    Front   Wheel, 
320. 

Tractor    Engines,    Four    Cyl- 
inder, 113. 

Tractor  Engines,  Parts  of  and 
Functions,  127. 

Tractor   Engines,    Three    Cyl- 
inder, 121. 


474 


Index 


Tractor  Engines,  Two  ( !yl- 
inder,  119. 

Tractor  Frame,   Typical,  285. 

Tractor  Frames,  Construction 
of,  285. 

Tractor  Front  Axles,  308. 

Tractor  Hitches,  401. 

Tractor  House  and  Workshop. 
350. 

Tractor  Houses,  Suggestions 
for,  353. 

Tractor  Houses,  Types  of, 
346. 

Tractor  Housing,  Why  Neces- 
sary, 343. 

Tractor,  How  to  Start,  333. 

Tractor,  How  to  Stop,  335. 

Tractor,  Many  Applications 
of,  43. 

Tractor  Mechanism,  Inspec- 
tion of,  368. 

Tractor  Motors,  Speeds  of,  62. 

Tractor  Motors,  Various  Types 
Compared,  62. 

Tractor  Operation,  Advice  on, 
341. 

Tractor  Power  for  Workshop, 
353. 

Tractor  Power  Plants,  Main 
Troubles  of,  368. 

Tractor  Suspension  on  Springs. 
29 1. 

Tractor,  Three  Wheel  Support, 
312. 

Tractor  Troubles,  Loss  of 
Power,  369. 

Tractor  Wheels,  Construction 
of,  293. 

Tractor  Wheels,  Front,  294. 

Tractor  Wheels,  Reinforce- 
ment of  Rim,  296. 


Tractor  Wheels,  Sizes  of,  294. 

Tractor  Wheel,  Suspension 
Spoke  Type,  296. 

Tractors,  Caterpillar  Tread 
Type,   88. 

Tractors,  Drawbar  Horse- 
power of,  95. 

Tractors,  Farm  Truck  Type, 
91. 

Tractors  for  Ploughing,  Sell- 
Contained,  82. 

Tractors  for  Small  Farms,  76. 

Tractors,  Large  Capacity,  82. 

Tractors,  Orchard  Type,  75. 

Tractors,  Parts  of,  Outlined, 
83. 

Tractors,  Power  Rating  Basis 
of,  92. 

Tractors,  Prime  Movers  for,  55. 

Tractors,  Steam  and  Gas  Com- 
pared, 55. 

Troubles  Due  to  Carbon  De- 
posits, 375. 

Troubles  With  Clutches,  396. 

Troubles   With   Gearing,   397. 

Troubles  With  Piston  and 
Rings,  383. 

Two-Cycle  Engines,  Operating 
Principle  of,  106. 

Two  Cylinder  Gas  Motors,  119. 

Two  Cylinder  Ignition  System, 
211. 

Two  Cylinder  Motors,  Balance 
of,   119. 

Two  Cylinder  Motors,  How 
They  Fire,  119. 

Types  of  Gas  Engines,  97. 

Typical  Tractor  Clutches,  250. 

U 

Utility  of  Clutch,  245. 


Index 


475 


Utility  of  Modern  Gas  Tractor, 
414. 


V 


Value  of  Deep  Ploughing,  77. 
Valve  Action  of  Gas  Motors, 

129. 
Valve    Grinding,    Method    of, 

377. 
Valve    Removal,    Method    of. 

377. 
Valve  Sizes,  137. 
Valve  System  of  Gas  Motors, 

136. 
Valve  Timing   by    Fly  Wheel 

Marks,  382. 
Valve  Timing,  Method  of,  380. 
Valves,    How    Operated,    139. 
Vaporizer,     Ellis     Two-Cycle 

Type,   176. 
Vertical  Cylinder  Motors,  Ad- 
vantages of,  117. 

W 

Wagons,  Power  Needed  for 
Hauling,  71. 

Water  Cooling  Systems,  Anti- 
freezing  Solutions,  445. 


Water,  Use  of  With  Kerosene 
Mixtures,  184. 

Watt,  Experiments  of,  41. 

Weight  Distribution  m  Gas 
Tractors,  68. 

Weight  of  Air,  161. 

Weight  of  Flywheels,  147. 

Wheel  Drive  by  Sprocket,  299. 

Wheel,  Hub  for,  300. 

Wheel,  One  for  Steering,  314. 

Wheel,  Spring  Buffer  Drive, 
298. 

Wheel,  Suspension  Spoke,  296. 

Wheels,  Extension  Rims  for, 
302. 

Wheels  for  Tractors,  293. 

Wheels,  Grouters  for,  300. 

Wheels,  Methods  of  Construc- 
tion,  294. 

Wheels,  Sizes  of,  294. 

Why  Differential  Gear  Is  Used. 
276. 

Why  Engines  Are  Oiled,  231. 

Why  Gas  Is  Compressed  Be- 
fore Ignition,  105. 

Why  Gas  Tractors  Are  Pop- 
ular, 57. 

Wood  Working  Tools  for 
Farm  Use,  365. 

Work  of  Tractor,  Cost  of.  51. 

Worm   Drive  Gearing,  325. 


^T*V 


PRACTICAL   SCIENTIFIC 
TECHNICAL 

— — «^**;^*— — 

EACH   BOOK  IN  THIS  CATALOGUE   IS  WRITTEN   BY 

AN   EXPERT  AND  IS  WRITTEN   SO  YOU 

CAN    UNDERSTAND   IT 


THE  NORMAN  t  HENLEY  PUBLISHING  COMPANY 

Publishers  of  Scientific  and  Practical  Books 
132  Nassau  Street  New  York,  U.S.  A. 


Any  book   in  this  Catalogue  sent  prepaid  on  receipt  of  price. 


SUBJECT     INDEX 


PAGE 

Accidents 18 

Air  Brakes 17,  19 

Arithmetics 20 

Automobiles 3 

Balloons 3 

Bevel  Gears 14 

Boilers 22 

Brazing 3 

Cams 15 

Car  Charts 4 

Change  Gear 14 

Charts 3,  4,  22 

Chemistry 23 

Coal  Mining 23 

Coke 4 

Compressed  Air 5 

Concrete 5 

Cyclopedia 4,  20 

Dictionaries 7 

Dies 7 

Drawing 8,  24 

Drop  Forging 7 

Dynamo 9,    10,  11 

Electricity 9,   10,   11,  12 

Engines  and  Boilers 22 

Factory  Management 12 

Flying  Machines 3 

Fuel 13 

Gas  Manufacturing 14 

Gas  Engines 13,  14 

Gears 14 

Heating,  Electric 9 

Hot  Water  Heating 27 

Horse-Power  Chart 4 

Hydraulics 15 

Ice  Making 15 

India  Rubber 25 

Interchangeable  Manufacturing 20 

Inventions 15 

Knots 15 

Lathe  Work 16 

Lighting  (Electric) 9 

Link  Motion 17 

Liquid  Air 16 

Locomotive  Boilers 18 

Locomotive  Engineering 17,   18,  19 

Machinist's  Books 20,  21,  22 


PAGE 

Manual  Training   22 

Marine  Engines 22 

Marine  Steam  Turbines 29 

Mechanical  Movements 20,  21 

Metal  Turning 16 

Milling  Machines 21 

Mining 22,  23 

Oil  Engines 13 

Patents 15 

Pattern  Making 23 

Perfumery 23 

Pipes 28 

Plumbing   24 

Producer  Gas 13 

Punches 7 

Railroad  Accidents 18 

Receipt  Book 23,  25 

Refrigeration 15 

Rope  Work 15 

Rubber  Stamps 25 

Saws 26 


Sheet  Metal  Working 

Shop  Tools 

Shop  Construction 

Shop  Management 

Sketching  Paper 

Smoke  Prevention 

Soldering 

Splices 

Steam  Engineering 26, 

Steam  Heating 

Steam  Pipes 

Steel 

Superheated  Steam 

Switchboards 9, 

Tapers 

Telephone 

Threads 

Tools 20, 

Turbines 

Ventilation 

Valve  Gear 

Valve  Setting 

Walschaert  Valve  Gear 

Watchmaking 

Wiring 9,   11, 

Wireless  Telephones  and  Telegraphy. . . . 


7 
21 
20 
20  1 

8 
i:5 

3 
15 
27 
27 
28 
28 
17 
11 
16 
12 
■22 
22 
29 
27 
19  I 
17 
19 
29  j 
12 
12  ! 


|^=  ANY     OF     THESE     BOOKS    PROMPTLY    SENT    PREPAID    TO    ANY    ADDRESS   IN - 
THE  WORLD    ON    RECEIPT    OF    PRICE. 

XSt^How   to   Remit. — By  Postal  Money  Order,  Express  Money  Order,  Bank  Draft 

or  Registered  Letter. 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

AUTOMOBILE 

THE  MODERN  GASOLINE  AUTOMOBILE— ITS  DESIGN,  CONSTRUCTION, 
MAINTENANCE  AND  REPAIR.     By  Victor  W.  Page,  M.  E. 

The  latest  and  most  complete  treatise  on  the  Gasoline  Automobile  ever  issued.  Written 
in  simple  language  by  a  recognized  authority,  familiar  with  every  branch  of  the  automobile 
industry.  Free  from  technical  terms.  Everything  is  explained  so  simply  that  anyone  of 
average  intelligence  may  gain  a  comprehensive  knowledge  of  the  gasoline  automobile. 
The  information  is  up-to-date  and  includes,  in  addition  to  an  exposition  of  principles  of 
construction  and  description  of  all  types  of  automobiles  and  their  components,  valuable 
money-saving  hints  on  the  care  and  operation  of  motor  cars  propelled  by  internal  combus- 
tion engines.  Among  some  of  the  subjects  treated  might  be  mentioned:  Torpedo  and  other 
symmetrical  body  forms  designed  to  reduce  air  resistance;  sleeve  valve,  rotary  valve  and 
other  tvpes  of  silent  motors;  increasing  tendency  to  favor  worm-gear  power-transmission; 
univers'al  application  of  magneto  ignition;  development  of  automobile  electric-lighting 
systems;  block  motors;  underslung  chassis;  application  of  practical  self-starters;  long  stroke 
and  offset  cylinder  motors;  latest  automatic  lubrication  systems;  silent  chains  for  valve 
operation  and  change-speed  gearing;  the  use  of  front  wheel  brakes  and  many  other  detail 
refinements. 

By  a  careful  study  of  the  pages  of  this  book  one  can  gain  practical  knowledge  of  automobile 
construction  that  will  save  time,  money  and  worry.  The  book  tells  you  just  what  to  do,  how 
and  when  to  do  it.  Nothing  has  been  omitted,  no  detail  has  been  slighted.  Every  part  of 
the  automobile,  its  equipment,  accessories,  tools,  supplies,  spare  parts  necessary,  etc.,  have 
been  discussed  comprehensively.  If  you  are  or  intend  to  become  a  motorist,  or  are  in 
any  way  interested  in  the  modern  Gasoline  Automobile,  this  is  a  book  you  cannot  afford  to 
be  without.  Nearly  600  6x9  pages — and  more  than  500  new  and  specially  made  detail  il- 
lustrations, as  well  as  many  full  page  and  double  page  plates,  showing  all  parts  of  the 
automobile.    Including  nine  large  folding  plates.    Price $2.50 

BALLOONS  AND  FLYING  MAGHINES 

MODEL  BALLOONS  AND  FLYING  MACHINES.  WITH  A  SHORT  ACCOUNT  OF 
THE  PROGRESS  OF  AVIATION.     By  J.  H.  Alexander. 

This  book  has  been  written  with  a  view  to  assist  those  who  desire  to  construct  a  model  airship 
or  flying  machine.  It  contains  five  folding  plates  of  working  drawings,  each  sheet  containing 
a  different  sized  machine.  Much  instruction  and  amusement  can  be  obtained  from  the  making 
and  flying  of  these  models. 

A  short  account  of  the  progress  of  aviation  is  included,  which  will  render  the  book  of  greater 
interest.  Several  illustrations  of  full  sized  airship  and  flying  machines  of  the  latest  types  are 
scattered  throughout  the  text.  This  practical  work  gives  data,  working  drawings,  and  details 
which  will  assist  materially  those  interested  in  the  problems  of  flight.  127  pages,  45  illustra- 
tions, 5  folding  plates.     Price $1.50 

BRAZING  AND   SOLDERING 

BRAZING  AND  SOLDERING.     By  James  F.  Hobart. 

The  only  book  that  shows  you  just  how  to  handle  any  job  of  brazing  or  soldering  that  comes 
{ilong;  tells  you  what  mixture  to  use,  how  to  make  a  furnace  if  you  need  one.  Full  of 
valuable  kinks.  The  fifth  edition  of  this  book  has  just  been  published,  and  to  it  much 
new  matter  and  a  large  number  of  tested  formulas  for  all  kinds  of  solders  and  fluxes  have 
been  added.     Illustrated 25  cents 

CHARTS 


MODERN  SUBMARINE  CHART— WITH  200  PARTS  NUMBERED  AND  NAMED. 

A  cross-section  view,  showing  clearly  and  distinctly  all  the  interior  of  a  Submarine  of  the 
latest  type.  You  get  more  information  from  this  chart,  about  the  construction  and  opera- 
tion of  a  Submarine,  than  in  any  other  way.  No  details  omitted — everything  is  accurate 
and  to  scale.  It  is  absolutely  correct  in  every  detail,  having  been  approved  by  Naval 
Engineers.  All  the  machinery  and  devices  fitted  in  a  modern  Submarine  Boat  are  shown,  and 
to  make  the  engraving  more  readily  understood  all  the  features  are  shown  in  operative  form, 
with  Officers  and  Men  in  the  act  of  performing  the  duties  assigned  to  them  in  service  con- 
ditions. This  CHART  IS  REALLY  AN  ENCYCLOPEDIA  OF  A  SUBMARINE.  It 
*s  educational  and  worth  many  times  its  cost.    Mailed  in  a  Tube  for 25  cents 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


■ 


BOX    CAR   CHART. 

A  chart  showing  the  anatomy  of  a  box  car,  having  every  part  of  the  car  numbered  and  its 
proper  name  given  in  a  reference  list 20  cents 

GONDOLA   CAR   CHART. 

A  chart  showing  the  anatomy  of  a  gondola  car,  having  every  part  of  the  car  numbered  and 
its  proper  reference  name  given  in  a  reference  list 20  cents 

PASSENGER   CAR    CHART. 

A  chart  showing  the  anatomy  of  a  passenger  car,  having  every  part  of  the  car  numbered  and 
its  proper  name  given  in  a  reference  list 20  cents 

WESTINGHOUSE    AIR-BRAKE    CHARTS. 

Chart  I. — Shows  (in  colors)  the  most  modern  Westinghouse  High  Speed  and  Signal  Equip- 
ment used  on  Passenger  Engines,  Passenger  Engine  Tenders,  and  Passenger  Cars.  Chart 
II. — -Shows  (in  colors)  the  Standard  Westinghouse  Equipment  for  Freight  and  Switch  En- 
gines, Freight  and  Switch  Engine  Tenders,  and  Freight  Cars.     Price  for  the  set     .     50  cents 

TRACTIVE   POWER   CHART. 

A  chart  whereby  you  can  find  the  tractive  power  or  drawbar  pull  of  any  locomotive,  without 
making  a  figure.  Shows  what  cylinders  are  equal,  how  driving  wheels  and  steam  pressure 
affect  the  power.  What  sized  engine  you  need  to  exert  a  given  drawbar  pull  or  anything 
you  desire  in  this  line 50  cents 

HORSE   POWER   CHART. 

Shows  the  horse  power  of  any  stationary  engine  without  calculation.  No  matter  what  the 
cylinder  diameter  of  stroke;  the  steam  pressure  or  cut-off;  the  revolutions,  or  whether  con- 
densing or  non-condensing,  it's  all  there.  Easy  to  use,  accurate,  and  saves  time  and  calcu- 
lations.    Especially  useful  to  engineers  and  designers ...     50  cents 

BOILER   ROOM    CHART.     By  Geo.  L.  Fowler. 

A  Chart — size  14  x  28  inches — showing  in  isometric  perspective  the  mechanisms  belonging 
in  a  modern  boiler  room.  Water  tube  boilers,  ordinary  grates  and  mechanical  stokers,  feed 
water  heaters  and  pumps  comprise  the  equipment.  The  various  parts  are  shown  broken  or 
removed,  so  that  the  internal  construction  is  fully  illustrated.  Each  part  is  given  a  reference 
number,  and  these,  with  the  corresponding  name,  are  given  in  a  glossary  printed  at  the  sides. 
This  chart  is  really  a  dictionary  of  the  boiler  room — the  names  of  more  than  200  parts  being 
given.     It  is  educational — worth  many  times  its  cost 25  cents 

CIVIL   ENGINEERING 

HENLEY'S    ENCYCLOPEDIA    OF    PRACTICAL    ENGINEERING     AND     ALLIED 

TRADES.     Edited  by  Joseph  G.  Horner,  A.  M.  I.  E.  M. 

This  set  of  five  volumes  contains  about  2,500  pages  with  thousands  of  illustrations,  including 
diagrammatic  and  sectional  drawings  with  full  explanatory  details.  This  work  covers  the 
entire  practice  of  Civil  and  Mechanical  Engineering.  The  best  known  experts  in  all  branches 
of  engineering  have  contributed  to  these  volumes.  The  Cyclopedia  is  admirably  well  adapted 
to  the  needs  of  the  beginner  and  the  self-taught  practical  man,  as  well  as  the  mechanical  en- 
gineer, designer,  draftsman,  shop  superintendent,  foreman,  and  machinist.  The  work  will  be 
found  a  means  of  advancement  to  any  progressive  man.  It  is  encyclopedic  in  scope,  thorough 
and  practical  in  its  treatment  of  technical  subjects,  simple  and  clear  in  its  descriptive  matter, 
and  without  unnecessary  technicalities  or  formulae.  The  articles  are  as  brief  as  may  be  and 
yet  give  a  reasonably  clear  and  explicit  statement  of  the  subject,  and  are  written  by  men  who 
have  had  ample  practical  experience  in  the  matters  of  which  they  write.  It  tells  you  all  you 
want  to  know  about  engineering  and  tells  it  so  simply,  so  clearly,  so  concisely,  that  one  cannot 
help  but  understand.  As  a  work  of  reference  it  is  without  a  peer.  $6.00  per  single  volume. 
For  complete  set  of  five  volumes,  price        $25.00 

COKE 

COKE— MODERN  COKING  PRACTICE;  INCLUDING  THE  ANALYSIS  OF 
MATERIALS  AND  PRODUCTS.  By  T.  H.  Byrom  and  J.  E.  Christopher. 
A  handbook  for  those  engaged  in  Coke  manufacture  and  the  recovery  of  By-products.  Fully 
illustrated  with  folding  plates.  It  has  been  the  aim  of  the  authors,  in  preparing  this  book, 
to  produce  one  which  shall  be  of  use  and  benefit  to  those  who  are  associated  with,  or  inter- 
ested in,  the  modern  developments  of  the  industry.      Contents:    I.  Introductory.     II.  Gen- 

4 


CATALOGUE  OF   GOOD,  PRACTICAL  BOOKS 

eral  Classification  of  Fuels.  III.  Coal  Washing.  IV.  The  Sampling  and  Valuation  of  Coal, 
Coke,  etc.  V.  The  Calorific  Power  of  Coal  and  Coke.  VI.  Coke  Ovens.  VII.  Coke  Ovens, 
continued.  VIII.  Coke  Ovens,  continued.  IX.  Charging  and  Discharging  of  Coke  Ovens, 
X.  Cooling  and  Condensing  Plant.  XI.  Gas  Exhausters.  XII.  Composition  and  Analysis 
of  Ammoniacal  Liquor.  XIII.  Working-up  of  Ammoniacal  Liquor.  XIV.  Treatment  of 
Waste  Gases  from  Sulphate  Plants.  XV.  Valuation  of  Ammonium  Sulphate.  XVI.  Direct 
Recoverv  of  Ammonia  from  Coke  Oven  Gases.  XVII.  Surplus  Gas  from  Coke  Oven.  Use- 
ful Tables.     Very  fully  illustrated.     Price S3. 50  net 

COMPRESSED   AIR 

COMPRESSED  AIR  IN  ALL  ITS  APPLICATIONS.     By  Gardner  D.   Hiscox. 

This  is  the  most  complete  book  on  the  subject  of  Air  that  has  ever  been  issued,  and  its  thirty- 
five  chapters  include  about  every  phase  of  the  subject  one  can  think  of.  It  may  be  called  an 
encyclopedia  of  compressed  air.  It  is  written  by  an  expert,  who.  in  its  665  pages,  has  dealt 
with  the  subject  in  a  comprehensive  manner,  no  phase  of  it  being  omitted.  Includes  the 
physical  properties  of  air  from  a  vacuum  to  its  highest  pressure,  its  thermodynamics,  com- 
pression, transmission  and  uses  as  a  motive  power;  in  the  Operation  of  Stationary  and  Port- 
able Machinery,  in  Mining.  Air  Tools,  Air  Lifts,  Pumping  of  Water,  Acids,  and  Oils;  the 
Air  Blast  for  Cleaning  and  Painting,  the  Sand  Blast  and  its  Work,  and  the  Numerous  Appli- 
ances in  which  Compressed  Air  is  a  Most  Convenient  and  Economical  Transmitter  of  Power 
for  Mechanical  Work.  Railway  Propulsion.  Refrigeration,  and  the  Various  Uses  to  which 
Compressed  Air  has  been  applied.  Includes  forty-four  tables  of  the  physical  properties  of 
air.  its  compression,  expansion,  and  volumes  required  for  various  kinds  of  work,  and  a  list  of 
patents  on  compressed  air  from  1875  to  date.  Over  500  illustrations,  5th  Edition,  revised  and 
enlarged.     Cloth  bound,  $5.00.     Half  Morocco,  price $6.50 

CONCRETE 

ORNAMENTAL  CONCRETE  WITHOUT  MOLDS.     By  A.  A.  Houghton. 

The  process  for  making  ornamental  concrete  without  molds  has  long  been  held  as  a  secret,  and 
now,  for  the  first  time,  this  process  is  given  to  the  public.  The  book  reveals  the  secret  and  is 
the  only  book  published  which  explains  a  simple,  practical  method  whereby  the  concrete  worker 
is  enabled,  by  employing  wood  and  metal  templates  of  different  designs'  to  mold  or  model  in 
concrete  any  Cornice,  Archivolt,  Column,  Pedestal,  Base  Cap,  Urn  or  Pier  in  a  monolithic 
form — right  upon  the  job.  These  may  be  molded  in  units  or  blocks,  and  then  built  up  to  suit  the 
specifications  demanded.   This  work  is  fully  illustrated,  with  detailed  engravings.    Price  $2.00 

CONCRETE  FROM  SAND  MOLDS.     By  A.  A.  Houghton. 

A  Practical  Work  treating  on  a  process  which  has  heretofore  been  held  as  a  trade  secret  by 
the  few  who  possessed  it,  and  which  will  successfully  mold  every  and  any  class  of  ornamental 
concrete  work.  The  process  of  molding  concrete  with  sand  molds  is  of  the  utmost  practical 
value,  possessing  the  manifold  advantages  of  a  low  cost  of  molds,  the  ease  and  rapidity  of 
operation,  perfect  details  to  all  ornamental  designs,  density,  and  increased  strength  of  the 
concrete,  perfect  curing  of  the  work  without  attention  and  the  easv  removal  of  the  molds  re- 
gardless of  any  undercutting  the  design  may  have.     192  pages.      Fully  illustrated.    Price  $2.00 

CONCRETE   WALL   FORMS.     By  A.  A.  Houghton. 

A  new  automatic  wall  clamp  is  illustrated  with  working  drawings.  Other  tvpes  of  wall 
forms,  clamps,  separators,  etc.,  are  also  illustrated  and  explained "    50  cents 

CONCRETE   FLOORS   AND   SIDEWALKS.    By  A.   A.    Houghton. 
The  molds  for   molding  squares,  hexagonal  and  many  other  styles  of  mosaic  floor  and  side- 
walk blocks  are  fully  illustrated  and  explained 50  cents 

PRACTICAL   CONCRETE  SILO  CONSTRUCTION.     By  A.  A.  Houghton. 
Complete  working  drawings  and    specifications  are  given  for  several  styles  of  concrete  silos 
with  illustrations  of   molds  for  monolithic  and  block  silos.     The  tables,  data  and  information 
presented  in  this  book  are  of  the  utmost  value  in  planning  and  constructing  all  forms  of  concrete 
silos 50  cents 

MOLDING  CONCRETE  CHIMNEYS,  SLATE  AND  ROOF  TILES.  Bv 
A.  A.  Houghton. 

The  manufacture  of  all  types  of  concrete  slate  and  roof  tile  is  fullv  treated.  Valuable  data 
on  all  forms  of  reinforced  concrete  roofs  are  contained  within  its  pages.  The  construction  of 
concrete  chimneys  by  block  and  monolithic  systems  is  fullv  illustrated  and  described.  A 
number  of  ornamental  designs  of  chimney  construction  with  molds  are  shown  in  this  valu- 
able treatise 50  cent* 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

MOLDING   AND    CURING    ORNAMENTAL    CONCRETE.     By  A.  A.  Houghton. 

The  proper  proportions  of  cement  and  aggregates  for  various  finishes,  also  the  methods  of 
thoroughly  mixing  and  placing  in  the  molds,  are  fully  treated.  An  exhaustive  treatise  on  this 
s  ibject  that  every  concrete  worker  will  find  of  daily  use  and  value 50  cents 

CONCRETE  MONUMENTS,  MAUSOLEUMS    AND  BURIAL  VAULTS.       By  A.  A. 

Houghton. 

The  molding  of  concrete  monuments  to  imitate  the  most  expensive  cut  stone  is  explained  in 

this  treatise,  with  working  drawings  of  easily  built  molds.      Cutting  inscriptions  and  designs 

is  also  fully  treated .50  cents 

MOLDING  CONCRETE  BATH  TUBS,  AQUARIUMS  AND  NATATORIUMS. 
By  A.  A.  Houghton. 

Simple  molds  and  instruction  are  given  for  molding  many  styles  of  concrete  bath  tubs, 
swimming  pools,  etc.  These  molds  are  easily  built  and  permit  rapid  and  successful 
work 50  cents 

CONCRETE  BRIDGES,  CULVERTS  AND  SEWERS.      By  A.  A.  Houghton. 

A  number  of  ornamental  concrete  bridges  with  illustrations  of  molds  are  given.  A  collapsible 
center  or  core  for  bridges,  culverts  and  sewers  is  fully  illustrated  with  detailed  instructions  for 
building  .     .     .  .     .  50  cents 

CONSTRUCTING    CONCRETE    PORCHES.     By  A.  A.  Houghton. 

A  number  of  designs  with  working  drawings  of  molds  are  fully  explained  so  anyone  can  easily 
construct  different  styles  of  ornamental  concrete  porches  without  the  purchase  of  expensive 
molds ,  50  cents 

MOLDING  CONCRETE  FLOWER  POTS,  BOXES,  JARDINIERES,  ETC.  By 
A.  A.  Houghton. 

The  molds  for  producing  many  original  designs  of  flower  pots,  urns,  flower  boxes,  jardinieres, 
etc.,  are  fully  illustrated  and  explained,  so  the  worker  can  easily  construct  and  operate 
same 50  cents 

MOLDING  CONCRETE  FOUNTAINS  AND  LAWN  ORNAMENTS.  By 
A.  A.  Houghton. 

The  molding  of  a  number  of  designs  of  lawn  seats,  curbing,  hitching  posts,  pergolas,  sun  dials 
and  other  forms  of  ornamental  concrete  for  the  ornamentation  of  lawns  and  gardens,  is 
fully  illustrated  and  described 50  cents 

.CONCRETE  FOR  THE  FARM  AND  SHOP.  By  A.  A.  Houghton. 

The  molding  of  drain  tile,  tanks,  cisterns,  fence  posts,  stable  floors,  hog  and  poultry  houses 
and  all  the  purposes  for  which  concrete  is  an  invaluable  aid  to  the  farmer  are  numbered 
among  the  contents  of  this  handy  volume , 50  cents 

POPULAR  HANDBOOK  FOR  CEMENT  AND  CONCRETE  USERS.  By  Myron 
H.  Lewis, 

This  is  a  concise  treatise  of  the  principles  and  methods  employed  in  the  manufacture  and  use 
of  cement  in  all  classes  of  modern  works.  The  author  has  brought  together  in  this  work  all 
the  salient  matter  of  interest  to  the  user  of  concrete  and  its  many  diversified  products.  The 
matter  is  presented  in  logical  and  systematic  order,  clearly  written,  fully  illustrated  and  free 
from  involved  mathematics.  Everything  of  value  to  the  concrete  user  is  given  including  kinds 
of  cement  employed  in  construction,  concrete  architecture,  inspection  and  testing,  water- 
proofing, coloring  and  painting,  rules,  tables,  working,  and  cost  data.  The  book  comprises 
thirty-three  chapters,  as  follows: 

Introductory.  Kinds  of  Cements  and  How  They  are  Made.  Properties,  Testing  and 
Requirements  of  Hydraidic  Cement.  Concrete  and  its  Properties.  Sand,  Broken  Stone  and 
Gravel  for  Concrete.  How  to  Proportion  the  Materials.  How  to  Mix  and  Place  Concrete. 
Forms  for  Concrete  Construction.  The  Architectural  and  Artistic  Possibilities  of  Concrete. 
Concrete  Residences.  Mortars.  Plasters  and  Stucco  and  How  to  Use  Them.  The  Artistic 
Treatment  of  Concrete  Surfaces.  Concrete  Building  Blocks.  The  Making  of  Ornamental 
Concrete.  Concrete  Pipes.  Fences,  Posts,  Etc.  Essential  Features  and  Advantages  of  Reen- 
forced  Concrete.  How  to  Design  Reenforced  Concrete  Beams,  Slabs  and  Columns.  Ex- 
planations of  the  Methods  and  Principles  in  Designing  Reenforced  Concrete  Beams  and 
Slabs.    Systems  of  Reenforcement  Employed.    Reenforced  Concrete  in  Factory  and  General 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

Building  Construction.  Concrete  in  Foundation  Work.  Concrete  Retaining  Walls,  Abut- 
ments, and  Bulkheads.  Concrete  Arches  and  Arch  Bridges.  Concrete  Beam  and  Girder 
Bridges.  Concrete  in  Sewerage  and  Drainage  Works.  Concrete  Tanks,  Dams  and  Reser- 
voirs. Concrete  Sidewalks.  Curbs  and  Pavements.  Concrete  in  Railroad  Constructions. 
The  Utility  of  Concrete  on  the  Farm.  The  Waterproofing  of  Concrete  Structure.  Grout 
or  Liquid  Concrete  and  Its  Use.  Inspection  of  Concrete  Work.  Cost  of  Concrete  Work. 
Some  of  the  special  features  of  the  book  are:  1.  The  Attention  Paid  to  the  Artistic  and 
Architectural  Side  of  Concrete  Work.  2.  The  Authoritative  Treatment  of  the  Problem 
of  Waterproofing  Concrete.  3.  An  Excellent  Summary  of  the  Rules  to  be  Followed  in 
Concrete  Construction.  4.  The  Valuable  Cost  Data  and  Useful  Tables  given.  A  valuable 
Addition  to  the  Library  of  Every  Cement  and  Concrete  User.  Price $2.50 

WATERPROOFING  CONCRETE.     By  Myron  H.  Lewis. 

Modern  Methods  of  Waterproofing  Concrete  and  Other  Structures.  A  condensed  statement 
of  the  Principles,  Rules,  and  Precautions  to  be  Observed  in  Waterproofing  and  Damp- 
proofing  Structures  and  Structural  Materials.   Paper  binding.    Illustrated.    Price.  .50  cents 

DICTIONARIES 

STANDARD  ELECTRICAL  DICTIONARY.     By  T.  O'Conor  Sloane. 

An  indispensable  work  to  all  interested  in  electrical  science.  Suitable  alike  for  the  student 
and  professional.  A  practical  hand-book  of  reference  containing  definitions  of  about  5,000 
distinct  words,  terms  and  phrases.  The  definitions  are  terse  and  concise  and  include  every 
term  used  in  electrical  science.  Recently  issued.  An  entirely  new  edition.  Should  be  in 
the  possession  of  all  who  desire  to  keep  abreast  with  the  progress  of  this  branch  of  science. 
Complete,  concise  and  convenient.      682  pages.     393  illustrations.     Price      ....     $3.00 

DIES— METAL   WORK 

DIES:  THEIR    CONSTRUCTION  AND    USE  FOR  THE  MODERN  WORKING  OF 

SHEET  METALS.   '  By  J.  V.  Woodworth. 

A  most  useful  book,  and-  one  which  should  be  in  the  hands  of  all  engaged  in  the  press  working 
of  metals;  treating  on  the  Designing,  Constructing,  and  Use  of  Tools,  Fixtures  and  Devices, 
together  with  the  manner  in  which  they  should  be  used  in  the  Power  Press,  for  the  cheap  and 
rapid  production  of  the  great  variety  of  sheet  metal  articles  now  in  use.  .It  is  designed  as  a 
guide  to  the  production  of  sheet  metal  parts  at  the  minimum  of  cost  with  the  maximum  of 
output.  The  hardening  and  tempering  of  Press  tools  and  the  classes  of  work  which  may  be 
produced  to  the  best  advantage  by  the  use  of  dies  in  the  power  press  are  fully  treated.  Its 
505  illustrations  show  dies,  press  fixtures  and  sheet  metal  working  devices,  the  descriptions 
of  which  are  so  clear  and  practical  that  all  metal-working  mechanics  will  be  able  to  understand 
how  to  design,  construct  and  use  them.  Many  of  the  dies  and  press  fixtures  treated  were 
either  constructed  by  the  author  or  under  his  supervision.  Others  were  built  by  skilful 
mechanics  and  are  in  use  in  large  sheet  metal  establishments  and  machine  shops.  Price    $3.00 

PUNCHES,  DIES   AND  TOOLS  FOR  MANUFACTURING  IN  PRESSES.      By  J.  V. 

Woodworth. 

This  work  is  a  companion  volume  to  the  author's  elementary  work  entitled  "Dies,  Their 
Construction  and  Use."  It  does  not  go  into  the  details  of  die  making  to  the  extent  of  the 
author's  previous  book,  but  gives  a  comprehensive  review  of  the  field  of  operations  carried  on 
by  presses.  A  large  part  of  the  information  given  has  been  drawn  from  the  author's  personal 
experience.  It  might  well  be  termed  an  Encyclopedia  of  Die  Making,  Punch  Making,  Die 
Sinking.  Sheet  Metal  Working,  and  Making  of  Special  Tools,  Sub-presses,  Devices  and  Mechani- 
cal Combinations  for  Punching,  Cutting,  Bending,  Forming,  Piercing,  Drawing,  Compressing 
and  Assembling  Sheet  Metal  Parts,  and  also  Articles  of  other  Materials  in  Machine  Tools. 
2d    Edition.     Price $4.00 

DROP  FORGING,  DIE  SINKING  AND  MACHINE  FORMING  OF  STEEL.      By  J.  V. 

Woodworth. 

This  is  a  practical  treatise  on  Modern  Shop  Practice.  Processes,  Methods.  Machines,  Tools, 
and  Details,  treating  on  the  Hot  and  Cold  Machine- Forming  of  Steel  and  Iron  Into  Finished 
shapes;  Together  with  Tools,  Dies,- and  Machinery  involved  in  the  manufacture  of  Duplicate 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

Forgings  and  Interchangeable  Hot  and  Cold  Pressed  Parts  from  Bar  and  Sheet  Metal. 
This  book  fills  a  demand  of  long  standing  for  information  regarding  drop  forging,  die-sinking 
and  machine  forming  of  steel  and  the  shop  practice  involved,  as  it  actually  exists  in  the 
modern  drop  forging  shop.  The  processes  of  die-sinking  and  force-making,  which  are  thor- 
oughly described  and  illustrated  in  this  admirable  work,  are  rarely  to  be  found  explained  in 
such  a  clear  and  concise  manner  as  is  here  set  forth.  The  process  of  die-sinking  relates  to 
the  engraving  or  sinking  of  the  female  or  lower  dies,  such  as  are  used  for  drop  forgings.  hot 
and  cold  machine  forging,  swedging  and  the  press  working  of  metals.  The  process  of  force- 
making  relates  to  the  engraving  or  raising  of  the  male  or  upper  dies  used  in  producing  the 
lower  dies  for  the  press-forming  and  machine-forging  of  duplicate  parts  of  metal. 

In  addition  to  the  arts  above  mentioned  the  book  contains  explicit  information  regarding 
the  drop  forging  and  hardening  plants,  designs,  conditions,  equipment,  drop  hammers, 
forging  machines,  etc..  machine  forging,  hydraulic  forging,  autogenous  welding  and  shop 
practice.  The  book  contains  eleven  chapters,  and  the  information  contained  in  these  chapters 
is  just  what  will  prove  most  valuable  to  the  forged  metal  worker.  All  operations  described 
in  the  work  are  thoroughly  illustrated  by  means  of  perspective  half-tones  and  outline  sketches 
of  the  machinery  employed.     300  detailed  illustrations.     Price $2.50 

DRAWING— SKETCHING    PAPER 


LINEAR   PERSPECTIVE   SELF-TAUGHT.     By  Herman  T.  C.  Kraus. 

This  work  gives  the  theory  and  practice  of  linear  perspective,  as  used  in  architectural,  engi- 
neering, and  mechanical  drawings.  Persons  taking  up  the  study  of  the  subject  by  themselves 
will  be  able  by  the  use  of  the  instruction  given  to  readily  grasp  the  subject,  and  by  reason- 
able practice  become  good  perspective  draftsmen.  The  arrangement  of  the  book  is  good ; 
the  plate  is  on  the  left-hand,  while  the  descriptive  text  follows  on  the  opposite  page,  so  as  to 
be  readily  referred  to.  The  drawings  are  on  sufficiently  large  scale  to  show  the  work  clearly 
and  are  plainly  figured.  The  whole  work  makes  a  very  complete  course  on  perspective  draw- 
ing, and  will  be  found  of  great  value  to  architects,  civil  and  mechanical  engineers,  patent 
attorneys,  art  designers,  engravers,  and  draftsmen $2.50 

PRACTICAL  PERSPECTIVE.     By  Richards  and  Colvin. 

Shows  just  how  to  make  all  kinds  of  mechanical  drawings  in  the  only  practical  perspective 
isometric.  Makes  everything  plain  so  that  any  mechanic  can  understand  a  sketch  or  drawing 
in  this  way.  Saves  time  in  the  drawing  room,  and  mistakes  in  the  shops.  Contains  practical 
examples  of  various  classes  of  work.     3rd  Edition 50  cents 

SELF-TAUGHT    MECHANICAL     DRAWING     AND      ELEMENTARY     MACHINE 

DESIGN.  By  F-  L.  Sylvester,  M.E.,  Draftsman,  with  additions  by  Erik  Oberg, 

associate  editor  of  "Machinery." 

This  is  a  practical  treatise  on  Mechanical  Drawing  and  Machine  Design,  comprising  the 
first  principles  of  geometric  and  mechanical  drawing,  workshop  mathematics,  mechanics, 
strength  of  materials  and  the  calculations  and  design  of  machine  details.  The  author's 
aim  has  been  to  adapt  this  treatise  to  the  requirements  of  the  practical  mechanic  and  young 
draftsman  and  to  present  the  matter  in  as  clear  and  concise  a  manner  as  possible.  To 
meet  the  demands  of  this  class  of  students,  practically  all  the  important  elements  of  machine 
design  have  been  dealt  with,  and  in  addition  algebraic  formulas  have  been  explained,  and 
the  elements  of  trigonometry  treated  in  the  manner  best  suited  to  the  needs  of  the  prac- 
tical man.  The  book  is  divided  into  20  chapters,  and  in  arranging  the  material,  mechan- 
ical drawing,  pure  and  simple,  has  been  taken  up  first,  as  a  thorough  understanding  of  the 
principles  of  representing  objects  facilitates  the  further  study  of  mechanical  subjects.  This 
is  followed  by  the  mathematics  necessary  for  the  solution  of  the  problems  in  machine  de- 
sign which  are  presented  later,  and  a  practical  introduction  to  theoretical  mechanics  and 
the  strength  of  materials.  The  various  elements  entering  into  machine  design,  such  as  cams, 
gears,  sprocket  wheels,  cone  pulleys,  bolts,  screws,  couplings,  clutches,  shafting  and  fly- 
wheels have  been  treated  in  such  a  way  as  to  make  possible  the  use  of  the  work  as  a  text- 
book for  a  continuous  course  of  study.  It  is  easily  comprehended  and  assimilated  even  by 
students  of  limited  previous  training.  330  pages,  215  engravings.     Price.     .     .     .     $2.00 

A  NEW  SKETCHING  PAPER. 

A  new  specially  ruled  paper  to  enable  you  to  make  sketches  or  drawings  in  isometric  perspective 
without  any  figuring  or  fussing.  It  is  being  used  for  shop  details  as  well  as  for  assembly 
drawings,  as  it  makes  one  sketch  do  the  work  of  three,  and  no  workman  can  help  seeing  just 
what  is  wanted.  Pads  of  40  sheets,  6x9  inches,  25  cents.  Pads  of  40  sheets,  9x12  inche6. 
50  cents;  40  sheets,  12x18,  Price $1.00 

8 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
ELECTRICITY 

ARITHMETIC  OF  ELECTRICITY.     By  Prof.  T.  O'Conor  Sloaxe. 

A  practical  treatise  on  electrical  calculations  of  all  kinds  reduced  to  a  series  of  rules,  all  of  the 
simplest  forms,  and  involving  only  ordinary  arithmetic;  each  rule  illustrated  by  one  or  more 
practical  problems,  with  detailed  solution  of  each  one.  This  book  is  classed  among  the  most 
useful  works  published  on  the  science  of  electricity  covering  as  it  does  the  mathematics  of 
electricity  in  a  manner  that  will  attract  the  attention  of  those  who  are  not  familiar  with  alge- 
braical formulas.     20th  Edition.      160  pages.     Price $1.00 

COMMUTATOR  CONSTRUCTION.     By  Wm.  Baxter,  Jr. 

The  business  end  of  any  dynamo  or  motor  of  the  direct  current  type  is  the  commutator.  This 
book  goes  into  the  designing,  building,  and  maintenance  of  commutators,  shows  how  to  locate 
troubles  and  how  to  remedy  them;   everyone  who  fusses  with  dynamos  needs  this.      25  cents 

DYNAMO  BUILDING  FOR  AMATEURS,  OR  HOW  TO  CONSTRUCT  A  FIFTY- WATT 
DYNAMO.     By  Arthur  J.  Weed,  Member  of  N.  Y.  Electrical  Society. 

A  practical  treatise  showing  in  detail  the  construction  of  a  small  dynamo  or  motor,  the  entire 
machine  work  of  which  can  be  done  on  a  small  foot  lathe.  Dimensioned  working  drawings 
are  given  for  each  piece  of  machine  work  and  each  operation  is  clearly  described.  This 
machine,  when  used  as  a  dynamo,  has  an  output  of  fifty  watts;  when  used  as  a  motor  it  will 
drive  a  small  drill  press  or  lathe.  It  can  be  used  to  drive  a  sewing  machine  on  any  and  all 
ordinary  work.  The  book  is  illustrated  with  more  than  sixty  original  engravings  showing 
the  actual  construction  of  the  different  parts.  Among  the  contents  are  chapters  on  1.  Fifty 
Watt  Dynamo.  2.  Side  Bearing  Rods.  3.  Field  Punchings.  4.  Bearings.  5.  Commu- 
tator. 6.  Pulley.  7.  Brush  Holders.  8.  Connection  Board.  9.  Armature  Shaft.  10. 
Armature.  11.  Armature  Winding.  12.  Field  Winding.  13.  Connecting  and  Starting. 
Price,  paper,  50  cents.     Cloth $1.00 

ELECTRIC  FURNACES  AND  THEIR  INDUSTRIAL  APPLICATIONS.    By  J.  Wright 

This  is  a  book  which  will  prove  of  interest  to  many  classes  of  people;  the  manufacturer  who 
desires  to  know  what  product  can  be  manufactured  successfully  in  the  electric  furnace,  the 
chemist  who  wishes  to  post  himself  on  the  electro-chemistry,  and  the  student  of  science  who 
merely  looks  into  the  subject  from  curiosity.  The  book  is  not  so  scientific  as  to  be  of  use 
only  to  the  technologist,  nor  so  unscientific  as  to  suit  only  the  tyro  in  electro-chemistry;  it 
is  a  practical  treatise  of  what  has  been  done,  and  of  what  is  being  done,  both  experimentally 
and  commercially  with  the  electric  furnace. 

In  important  processes  not  only  are  the  chemical  equations  given,  but  complete  thermal  data 
are  set  forth  and  both  the  efficiency  of  the  furnace  and  the  cost  of  the  product  are  worked 
out ,  thus  giving  the  work  a  solid  commercial  value  aside  from  its  efficacy  as  a  work  of  reference. 
The  practical  features  of  furnace  building  are  given  the  space  that  the' subject  deserves.  The 
forms  and  refractory  materials  used  in  the  linings,  the  arrangement  of  the  connections  to  the 
electrodes,  and  other  important  details  are  explained.  288  pages.  New  Revised  Edition. 
Fully  illustrated.    Price $3.00 

ELECTRIC  LIGHTING  AND  HEATING  POCKET  BOOK.     By  Sydney  F.  Walker. 

This  book  puts  in  convenient  form  useful  information  regarding  the  apparatus  which  is  likely 
to  be  attached  to  the  mains  of  an  electrical  company.  Tables  of  units  and  equivalents  are 
included  and  useful  electrical  laws  and  formulas  are  stated. 

One  section  is  devoted  to  dynamos,  motors,  transformers  and  accessory  apparatus;  another 
to  accumulators,  another  to  switchboards  and  related  equipment,  a  fourth  to  a  description 
of  various  systems  of  distribution,  a  fifth  section  to  a  discussion  of  instruments,  both  fur 
portable  use  and  switchboards;  another  section  deals  with  electric  lamps  of  various  types 
and  accessory  appliances,  and  the  concluding  section  is  given  up  to  electric  heating  apparatus. 
In  each  section  a  large  number  of  commercial  types  are  described,  frequent  tables  of  dimen- 
sions being  included.  A  great  deal  of  detail  information  of  each  line  of  apparatus  is  given 
and  the  illustrations  shown  give  a  good  idea  of  the  gt-ru-ral  appearance  of  the  apparatus  under 
discussion.  The  book  also  contains  much  valuable  information  for  the  central  station  engi- 
neer.    438  pages.     300  engravings.     Bound  in  leather  pocket  book  form.     Price     .       $3.00 

ELECTRIC  WIRING,  DIAGRAMS  AND  SWITCHBOARDS.    By  Newtox  Harrisox. 

\  thoroughly  practical  treatise  covering  the  subject  of  Electric  Wiring  in  all  its  branches, 
including  explanations  and  diagrams  which  are  thoroughly  explicit  and  greatly  simplify 
the  subject.  Practical  every-day  problems  in  wiring  are  presented  and  the  method  of 
obtaining  intelligent  results  clearly  shown.     Only  arithmetic  is  used.     Ohm's  law  is  given 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

a  simple  explanation  with  reference  to  wiring  for  direct  and  alternating  currents.  The  funda- 
mental principle  of  drop  of  potential  in  circuits  is  shown  with  its  various  applications.  The 
simple  circuit  is  developed  with  the  position  of  mains,  feeders  and  branches;  their  treat- 
ment as  a  part  of  a  wiring  plan  and  their  employment  in  house-wiring  clearly  illustrated. 
Some  simple  facts  about  testing  are  included  in  connection  with  the  wiring.  Molding 
and  conduit  work  are  given  careful  consideration;  and  switchboards  are  systematically 
treated,  built  up  and  illustrated,  showing  the  purpose  they  serve,  for  connection  with  the 
circuits,  and  to  shunt  and  compound  wound  machines.  The  simple  principles  of  switchboard 
construction,  the  development  of  the  switchboard,  the  connections  of  the  various  instru- 
ments including  the  lightning  arrester,  are  also  plainly  set  forth. 

Alternating  current  wiring  is  treated,  with  explanations  of  the  power  factor,  conditions 
calling  for  various  sizes  of  wire  and  a  simple  way  of  obtaining  the  sizes  for  single-phase,  two- 
phase  and  three-phase  circuits.  This  is  the  only  complete  work  issued  showing  and  telling 
you  what  you  should  know  about  direct  and  alternating  current  wiring.  It  is  a  ready  refer- 
ence. The  work  is  free  from  advanced  technicalities  and  mathematics,  arithmetic  being  used 
throughout.  It  is  in  every  respect  a  handy,  well-written,  instructive,  comprehensive 
volume  on  wiring  for  the  wireman,  foreman,  contractor,  or  electrician.  272  pages;  105  illus- 
trations.     Price $1.50 

ELECTRIC  TOY  MAKING,  DYNAMO  BUILDING,  AND  ELECTRTC  MOTOR  CON- 
STRUCTION.    By  Prof.  T.  O'Conor  Sloane. 

This  work  treats  of  the  making  at  home  of  electrical  toys,  electrical  apparatus,  motors,  dynamos 
and  instruments  in  general,  and  is  designed  to  bring  within  the  reach  of  young  and  old  the 
manufacture  of  genuine  and  useful  electrical  appliances.  The  work  is  especially  designed  for 
amateurs  and  young  folks. 

Thousands  of  our  young  people  are  daily  experimenting,  and  busily  engaged  in  making  electrical 
toys  and  apparatus  of  various  kinds.  The  present  work  is  just  what  is  wanted  to  give  the 
much  needed  information  in  a  plain,  practical  manner,  with  illustrations  to  make  easy  the 
carrying  out   of    the  work.     19th   Edition.     Price $1.00 

ELECTRICIAN'S  HANDY  BOOK.     By  Prof.  T.  O'Conor  Sloane. 

This  work  of  768  pages  is  intended  for  the  practical  electrician  who  has  to  make  things  go. 
The  entire  field  of  electricity  is  covered  within  its  pages.  Among  some  of  the  subjects  treated 
are:  The  Theory  of  the  Electric  Current  and  Circuit,  Electro-Chemistry,  Primary  Batteries, 
Storage  Batteries,  Generation  and  Utilization  of  Electric  Powers,  Alternating  Current,  Arma- 
ture Winding,  Dynamos  and  Motors,  Motor  Generators,  Operation  of  the  Central  Station 
Switchboards,  Safety  Appliances,  Distribution  of  Electric  Light  and  Power,  Street  Mains, 
Transformers,  Arc  and  Incandescent  Lighting,  Electric  Measurements,  Photometry,  Electric 
Railways,  Telephony,  Bell-Wiring,  Electro-Plating,  Electric  Heating,  Wireless  Telegraphy,  etc. 
It  contains  no  useless  theory;  everything  is  to  the  point.  It  teaches  you  just  what  you  want 
to  know  about  electricity.  It  is  the  standard  work  published  on  the  subject.  Forty-one 
chapters,  610  engravings,  handsomely  bound  in  red  leather  with  title  and  edges  in  gold.     Price: 

$3.50 

ELECTRICITY  IN  FACTORIES  AND  WORKSHOPS,  ITS  COST  AND  CONVENIENCE. 
By  Arthur  P.  Haslam. 

A  practical  book  for  power  producers  and  power  users  showing  what  a  convenience  the  electric 
motor,  in  its  various  forms,  has  become  to  the  modern  manufacturer.  It  also  deals  with  the 
conditions  which  determine  the  cost  of  electric  driving,  and  compares  this  with  other  methods 
of  producing  and  utilizing  power. 

Among  the  chapters  contained  in  the  book  are:  The  Direct  Current  Motor;  The  Alternating 
Current  Motor;  The  Starting  and  Speed  Regulation  of  Electric  Motors;  The  Rating  and 
Efficiency  of  Electric  Motors;  The  Cost  of  Energy  as  Affected  by  Conditions  of  Working,  The 
Question  for  the  Small  Power  User;  Independent  Generating  Plants;  Oil  and  Gas  Engine 
Plants;  Steam  Plants;  Power  Station  Tariffs;  The  Use  of  Electric  Power  in  Textile  Factories; 
Electric  Power  in  Printing  Works;  The  Use  of  Electric  Power  in  Engineering  Workshops 
Miscellaneous  Application  of  Electric  Power;  The  Installation  of  Electric  Motors;  The  Lighting 
of  Industrial  Establishments.     312  pages.     Very  fully  illustrated.     Price       ....     $2.50 

ELECTRICITY  SIMPLIFIED.     By  Prof.  T.  O'Conor  Sloane. 

The  object  of  "Electricity  Simplified"  is  to  make  the  subject  as  plain  as  possible  and  to  show 
what  the  modern  conception  of  electricity  is;  to  show  how  two  plates  of  different  metals 
immersed  in  acid  can  send  a  message  around  the  globe;  to  explain  how  a  bundle  of  copper  wire 
rotated  by  a  steam  engine  can  be  the  agent  in  lighting  our  streets,  to  tell  what  the  volt,  ohm 
and  ampere  are,  and  what  high  and  low  tension  mean;  and  to  answer  the  questions  that 
perpetually  arise  in  the  mind  in  this  age  of  electricity.    172  pages.    Illustrate.    Price  $  1.00 

IO 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

HOUSE  WIRING.     By  Thomas  W.  Poppe. 

This  work  describes  and  illustrates  the  actual  installation  of  Electric  Light  Wiring,  the  manner 
in  which  the  work  should  be  done,  and  the  method  of  doing  it.  The  book  can  be  conveniently 
carried  in  the  pocket.  It  is  intended  for  the  Electrician,  Helper  and  Apprentice.  It 
solves  all  Wiring  Problems,  and  contains  nothing  that  conflicts  with  the  rulings  of  the  Nation- 
al Board  of  Fire  Underwriters.  It  gives  just  the  information  essential  to  the  Successful 
Wiring  of  a  Building.  Among  the  subjects  treated  are:  Locating  the  Meter.  Panel  Boards. 
Switches.  Plug  Receptacles.  Brackets.  Ceiling  Fixtures.  The  Meter  Connections.  The 
Feed  Wires.  The  Steel  Armored  Cable  System.  The  Flexible  Steel  Conduit  System.  The 
Ridig  Conduit  System.  A  digest  of  the  Xational  Board  of  Fire  Underwriters'  rules  relating 
to  metallic  wiring  systems.  Various  switching  arrangements  explained  and  diagrammed. 
The  easiest  method  of  testing  the  Three  and  Four-way  circuits  explained.  The  grounding 
of  all  metallic  wiring  systems  and  the  reason  for  doing  so  shown  and  explained.  The  in- 
sulation of  the  metal  parts  of  lamp  fixtures  and  the  reason  for  the  same  described  and 
illustrated.    125  pages.    Fully  illustrated.    Flexible  cloth.     Price 50  cents 

HOW  TO  BECOME  A  SUCCESSFUL  ELECTRICIAN-  By  Prof.  T.  O 'Conor  Sloan  e. 

Every  young  man  who  wishes  to  become  a  successful  electrician  should  read  this  book.  It  tel's 
in  simple  language  the  surest  and  easiest  way  to  become  a  successful  electrician.  The  studies 
to  be  followed,  methods  of  work,  field  of  operation  and  the  requirements  of  the  successful 
electrician  are  pointed  out  and  fully  explained.  Every  young  engineer  will  find  this  an  ex- 
cellent stepping-stone  to  more  advanced  works  on  electricity  which  he  must  master  before 
success  can  be  attained.  Many  young  men  become  discouraged  at  the  very  outstart  by 
attempting  to  read  and  study  books  that  are  far  beyond  their  comprehension.  This  book 
serves  as  the  connecting  link  between  the  rudiments  taught  in  the  public  schools  and  the  real 
studv  of  electricity.  It  is  interesting  from  cover  to  cover.  Fifteenth  edition.  202  pages. 
Illustrated.     Price         $1.00 

MANAGEMENT    OF   DYNAMOS.     By  Lummis-Paterson. 

A  handbook  of  theory  and  practice.  This  work  is  arranged  in  three  parts.  The  first  part 
covers  the  elementary  theory  of  the  dynamo.  The  second  part,  the  construction  and  action 
of  the  different  classes  of  dynamos  in  common  use  are  described;  while  the  third  part  relates 
to  such  matters  as  affect  the  practical  management  and  working  of  dynamos  and  motors. 
The  following  chapters  are  contained  in  the  book:  Electrical  Units:  Magnetic  Principles; 
Theory  of  the  Dynamo;  Armature;  Armature  in  Practice;  Field  Magnets;  Field  Magnets  in 
Practice;  Regulating  Dynamos:  Coupling  Dynamos;  Installation,  Running,  and  Maintenance 
of  Dynamos;  Faults  in  Dyn-mos;  Faults  in  Armatures;  Motors.  292  pages.  117  illustra- 
tions'.    Price $1.50 

STANDARD  ELECTRICAL  DICTIONARY.     By  T.  O'Conor  Sloane. 

An  indispensable  work  to  all  interested  in  electrical  science.  Suitable  alike  for  the  student 
and  professional.  A  practical  hand-book  of  reference  containing  definitions  of  about  5,000 
distinct  words,  terms  and  phrases.  The  definitions  are  terse  and  concise  and  include  every 
term  used  in  electrical  science.  Recently  issued.  An  entirely  new  edition.  Should  be  in  the 
possession  of  all  who  desire  to  keep  abreast  with  the  progesss  of  this  branch  of  science.  In 
its  arrangement  and  typography  the  book  is  very  convenient.  The  word  or  term  defined  is 
printed  in  black-faced*  type  which  readily  catches  the  eye,  while  the  body  of  the  page  is  in 
smaller  but  distinct  type.  The  definitions  are  well  worded,  and  so  as  to  be  understood  by 
the  non-technical  reader.  The  general  plan  seems  to  be  to  give  an  exact,  concise  definition, 
and  then  amplify  and  explain  in  a  more  popular  way.  Synonyms  are  also  given,  and  refer- 
ences to  other  words  and  phrases  are  made.  A  very  complete  and  accurate  index  of  fifty 
pages  is  at  the  end  of  the  volume;  and  as  this  index  contains  all  synonyms,  and  as  all  phrases 
are  indexed  in  every  reasonable  combination  of  words,  reference  to  the  proper  place  in  the 
body  of  the  book  is  readily  made.  It  is  difficult  to  decide  how  far  a  book  of  this  character 
is  to  keep  the  dictionary  form,  and  to  what  extent  it  may  assume  the  encyclopedia  form. 
For  some  purposes,  concise,  exactly  worded  definitions  are  needed;  for  other  purposes,  more 
extended  descriptions  are  required.  This  book  seeks  to  satisfy  both  demands,  and  does  it 
with  considerable  success.  Complete,  concise,  and  convenient.  682  pages.  393  illustra- 
tions.    Twelfth  edition.     Price $3.00 

SWITCHBOARDS.     By  William  Baxter,  Jr. 

This  book  appeals  to  every  engineer  and  electrician  who  wants  to  know  the  practical  side  of 
things.  It  takes  up  all  sorts  and  conditions  of  dynamos,  connections  and  circuits  and  shows 
by  diagram  and  illustration  just  how  the  switchboard  should  be  connected.  Includes  direct 
and  alternating  current  boards,  also  those  for  arc  lighting,  incandescent,  and  power  circuits. 
Special  treatment  on  high  voltage  boards  for  power  transmission.  2d  Edition.  190  pages. 
Illustrated.     Price $1.50 

II 


CATALOGUE  OF   GOOD,  PRACTICAL  BOOKS 

TELEPHONE  CONSTRUCTION,  INSTALLATION,  WIRING,  OPERATION  AND 
MAINTENANCE.     By  W.  H.  Radcliffe  and  H.  C.  Cushing. 

This  book  gives  the  principles  of  construction  gnd  operation  of  both  the  Bell  and  Independent 
instruments;  approved  methods  of  installing  and  wiring  them;  the  means  of  protecting  them 
from  lightning  and  abnormal  currents;  their  connection  together  for  operation  as  series  or 
bridging  stations;  and  rules  for  their  inspection  and  maintenance.  Line  wiring  and  the  wir- 
ing and  operation  of  special  telephone  systems  are  also  treated. 

Intricate  mathematics  are  avoided,  and  all  apparatus,  circuits  and  systems  are  thoroughly 
described.  The  appendix  contains  definitions  of  units  and  terms  used  in  the  text.  Selectee- 
wiring  tables,  which  are  very  helpful,  are  also  included.  Among  the  subjects  treated  are 
Construction,  Operation,  and  installation  of  Telephone  Instruments,  Inspection  and  Main- 
tenance of  Telephone  Instruments;  Telephone  Line  Wiring;  Testing  Telephone  Line  Wires 
and  Cables;  WTiring  and  Operation  of  Special  Telephone  Systems,  etc.  100  pages,  125  illus- 
trations  $1.00 

WIRELESS    TELEGRAPHY    AND     TELEPHONY    SIMPLY  EXPLAINED. 

By  Alfred  P.  Morgan. 

This  is  undoubtedly  one  of  the  most  complete  and  comprehensible  treatises  on  the  subject 
ever  published,  and  a  close  study  of  its  pages  will  enable  one  to  master  all  the  details  of  the 
wireless  transmission  of  messages.  The  author  has  filled  a  long  felt  want  and  has  succeeded 
in  furnishing  a  lucid,  comprehensible  explanation  in  simple  language  of  the  theory  and 
practice  of  wireless  telegraphy  and  telephony. 

Among  the  contents  are:  Introductory;  Wireless  Transmission  and  Receptiorv — The 
Aerial  System.  Earth  Connections — The  Transmitting  Apparatus,  Spark  Coils  and  Trans- 
formers. Condensers,  Helixes,  Spark  Gaps,  Anchor  Gaps,  Aerial  Switches — The  Receiving 
Apparatus,  Detectors,  etc. — Tuning  and  Coupling,  Tuning  Coils,  Loose  Couplers,  Variable 
Condensers,  Directive  Wave  Systems — Miscellaneous  Apparatus,  Telephone  Receivers, 
Range  of  Stations,  Static,  Interference — Wireless  Telephones,  Sound  and  Sound  Waves,  The 
Vocal  Cords  and  Ear — Wireless  Telephones,  How  Sounds  are  changed  into  Electric  Waves — 
Wireless  Telephones,  The  Apparatus — Summary.     200  pages.    150  engravings.    Price  $1.00 

WIRELESS  TELEPHONES  AND  HOW  THEY  WORK.    By  James  Erskine-Murray. 

This  work  is  free  from  elaborate  details  and  aims  at  giving  a  clear  survey  of  the  way  in  which 
Wireless  Telephones  work.  It  is  intended  for  amateur  workers  and  for  those  whose  knowledge 
of  electricity  is  slight.  Chapters  contained:  How  We  Hear;  Historical;  The  Conversion  of 
Sound  into  Electric  Waves;  Wireless  Transmission;  The  Production  of  Alternating  Currents 
of  High  Frequency;  How  the  Electric  Waves  are  Radiated  and  Received;  The  Receiving 
Instruments;  Detectors;  Achievements  and  Expectations;  Glossary  of  Technical  Words, 
Cloth.     Price $1.00 

WIRING  A  HOUSE.     By  Herbert  Pratt. 

Shows  a  house  already  built;  tells  just  how  to  start  about  wiring  it;  where  to  begin;  what 
wire  to  use;  how  to  run  it  according  to  Insurance  Rules;  in  fact  just  the  information  you  need. 
Directions  apply  equally  to  a  shop.     Fourth  edition 25  cents 

FACTORY  MANAGEMENT,  ETC. 


MODERN  MACHINE  SHOP  CONSTRUCTION,  EQUIPMENT  AND  MANAGEMENT. 

By  O.  E.  Perrigo,  M.E. 

The  only  work  published  that  describes  the  modern  machine  shop  or  manufacturing  plant  from 
the  time  the  grass  is  growing  on  the  site  intended  for  it  until  the  finished  product  is  shipped. 
By  a  careful  study  of  its  thirty-two  chapters  the  practical  man  may  economically  build, 
efficiently  equip,  and  successfully  manage  the  modern  machine  shop  or  manufacturing  estab- 
ishment.  Just  the  book  needed  by  those  contemplating  the  erection  of  modern  shop  buildings, 
the  re-building  and  re-organization  of  old  ones,  or  the  introduction  of  modern  shop  methods, 
time  and  cost  system.  It  is  a  book  written  and  illustrated  by  a  practical  shop  man  for  practical 
shop  men  who  are  too  busy  to  read  theories  and  want  facts.  It  is  the  most  complete  all  around 
book  of  its  kind  ever  published.  It  is  a  practical  book  for  practical  men,  from  the  apprentice 
in  the  shop  to  the  president  in  the  office.  It  minutely  describes  and  illustrates  the  most  simple 
and  yet  the  most  efficient  time  and  cost  system  yet  devised.     Price $5.00 

12 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
FUEL 

COMBUSTION  OF  COAL  AND  THE  PREVENTION  OF  SMOKE.    By  Wm.  M.  Barr. 

This  book  has  been  prepared  with  special  reference  to  the  generation  of  heat  by  the  combus- 
tion of  the  common  fuels  found  in  the  United  States,  and  deals  particularly  with  the  condi- 
tions necessary  to  the  economic  and  smokeless  combustion  of  bituminous  coals  in  Stationary 
and  Locomotive  Steam  Boilers. 

The  presentation  of  this  important  subject  is  systematic  and  progressive.  The  arrangement 
of  the  book  is  in  a  series  of  practical  questions  to  which  are  appended  accurate  answers, 
which  describe  in  language,  free  from  technicalities,  the  several  processes  involved  in  the 
furnace  combustion  of  American  fuels;  it  clearly  states  the  essential  requisites  for  perfect 
combustion,  and  points  out  the  best  methods  for  furnace  construction  for  obtaining  the  great- 
est quantity  of  heat  from  any  given  quality  of  coal.  Nearly  350  pages,  fully  illustrated. 
Price 12 $1.00 

SMOKE    PREVENTION    AND    FUEL    ECONOMY.     By  Booth  and  Kershaw. 

A  complete  treatise  for  all  interested  in  smoke  prevention  and  combustion,  being  based  on 
the  German  work  of  Ernst  Schmatolla,  but  it  is  more  than  a  mere  translation  of  the  German 
treatise,  much  being  added.  The  authors  show  as  briefly  as  possible  the  principles  of  fuel 
combustion,  the  methods  which  have  been  and  are  at  present  in  use,  as  well  as  the  proper 
scientific  methods  for  obtaining  all  the  energy  in  the  coal  and  burning  it  without  smoke. 
Considerable  space  is  also  given  to  the  examination  of  the  waste  gases,  and  several  of  the 
representative  English  and  American  mechanical  stoker  and  similar  appliances  are  described. 
The  losses  carried  away  in  the  waste  gases  are  thoroughly  analyzed  and  discussed  in  the  Ap- 

Eendix,  and  abstracts  are  also  here  given  of  various  patents  on  combustion  apparatus.     The 
ook  is  complete  and   contains  much  of  value  to  all  who  have  charge  of  large  plants.     194 
pages.     Illustrated.     Price $2.50 

GAS   ENGINES   AND    GAS 

GASOLINE  ENGINES  :  THEIR  OPERATION,  USE  AND  CARE.     By  A.  Hyatt 

Verrill. 

The  Simplest,  Latest  and  Most  Comprehensive  popular  work  published  on  Gasoline  Engines 
describing  what  the  Gasoline  engine  is;  its  construction  and  operation;  how  to  install  it; 
how  to  select  it;  how  to  use  it  and  how  to  remedy  troubles  encountered.  Intended  for  owners. 
Operators  and  Users  of  Gasoline  Motors  of  all  kinds.  This  work  fully  describes  and  illus- 
trates the  various  types  of  Gasoline  engines  used  in  Motor  Boats.  Motor  Vehicles  and 
Stationary  Work.  The  parts,  accessories  and  Appliances  are  described,  with  chapters  on 
ignition,  fuel,  lubrication,  operation  and  engine  troubles.  Special  attention  is  given  to  the 
care,  operation  and  repair  of  motors  with  useful  hints  and  suggestions  on  emergency  re- 
pairs and  make-shifts.  A  complete  glossary  of  technical  terms  and  an  alphabetically  ar- 
ranged table  of  troubles  and  their  symptoms  form  most  valuable  and  unique  features  of  this 
manual.  Nearly  every  illustration  in  the  book  is  original,  having  been  made  by  the  author. 
Every  page  is  full  of  interest  and  value.  A  book  which  you  cannot  afford  to  be  without.  320 
pages.    Nearly  150  specially  made  engravings.     Price $1.50 

GAS,  GASOLINE,  AND  OIL  ENGINES.     By  Gardner  D.  Hiscox. 

Just  issued,  20th  revised  and  enlarged  edition.  Every  user  of  a  gas  engine  needs  this  book. 
Simple,  instructive,  and  right  up-to-date.  The  only  complete  work  on  the  subject.  Tells 
all  about  the  running  and  management  of  gas,  gasoline  and  oil  engines,  as  designed  and  manu- 
factured in  the  United  States.  Explosive  motors  for  stationary,  marine  and  vehicle  power  are 
fully  treated,  together  with  illustrations  of  their  parts  and  tabulated  sizes,  also  their  care  and 
running  are  included.  Electric  ignition  by  induction  coil  and  jump  spark  are  fully  explained 
and  illustrated,  including  valuable  information  on  the  testing  for  economy  and  power  and  the 
erection  of  power  plants. 

The  rules  and  regulations  of  the  Board  of  Fire  Underwriters  in  regard  to  the  installation  and 
management  of  gasoline  motors  is  given  in  full,  suggesting  the  safe  installation  of  explosive 
motor  power.'  A  list  of  United  States  Patents  issued  on  gas,  gasoline,  and  oil  engines  and  their 
adjuncts  from  1875  to  date  is  included.     484  pages.      410  engravings     Price     .     .     .        $3.50 

MODERN  GAS  ENGINES  AND  PRODUCER  GAS  PLANTS.    By  R.  E.  Mathot,  M.E. 

A  guide  for  the  gas  engine  designer,  user,  and  engineer  in  the  construction,  selection,  purchase 
installation,  operation,  and  maintenance  of  gas  engines.  More  than  one  book  on  gas  engines 
has  been  written,  but  not  one  has  thus  far  even  encroached  on  the  field  covered  by  this  book. 
Above  all   Mr.  Mat  hot's  work  is  a  practical  guide.     Recognizing  the  need  of  a  volume  that 

i3 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

would  assist  the  gas  engine  user  in  understanding  thoroughly  the  motor  upon  which  he  depends 
for  power,  the  author  has  discussed  his  subject  without  the  help  of  any  mathematics  and 
without  elaborate  theoretical  explanations.  Every  part  of  the  gas  engine  is  described  in  detail, 
tersely,  clearly,  with  a  thorough  understanding  of  the  requirements  of  the  mechanic.  Helpful 
suggestions  as  to  the  purchase  of  an  engine,  its  installation,  care,  and  operation  form  a  most 
valuable  feature  of  the  work.     320  pages.     175  detailed  illustrations.     Price      .     .     .     $2.50 

GAS  ENGINE  CONSTRUCTION,  OR   HOW  TO   BUILD  A  HALF-HORSE-POWER 

GAS  ENGINE.     By  Parsell  and  Weed. 

A  practical  treatise  of  300  pages  describing  the  theory  and  principles  of  the  action  of  Gas 
Engines  of  various  types  and  the  design  and  construction  of  a  half-horse  power  Gas  Engim-.  with 
illustrations  of  the  work  in  actual  progress,  together  with  the  dimensioned  working  drawings 
giving  clearly  the  sizes  of  the  various  details;  for  the  student,  the  scientific  investigator  and  the 
amateur  mechanic. 

Tnis  book  treats  of  the  subject  more  from  the  standpoint  of  practice  than  that  of  theory.  The 
principles  of  operation  of  Gas  Engines  are  clearly  and  simply  described  and  then  the  actual 
construction  of  a  half-horse  power  engine  is  taken  up,  step  by  step,  showing  in  detail  the  making 
of  the  Gas  Engine.     3d  Edition.     300  pages.     Price $2.50 

THE  GASOLINE  ENGINE  ON  THE  FARM:    ITS   OPERATION,  REPAIR 

AND   USES.     By  Xeno  W.  Putnam. 

This  is  a  practical  treatise  on  the  Gasoline  and  Kerosene  engine  intended  for  the  man  who 
wants  to  know  just  how  to  manage  his  engine  and  how  to  apply  it  to  all  kinds  of  farm  work 
to  the  best  advantage. 

The  book  includes  selecting  the  most  suitable  engine  for  farm  work,  its  most  convenient  and 
efficient  installation,  with  chapters  on  troubles,  their  remedies  and  how  to  avoid  them. 
The  care  and  management  of  the  farm  tractor  in  plowing,  harrowing,  harvesting  and  road 
grading  are  fully  covered;  also  plain  directions  are  given  for  handling  the  tractor  on  the  road. 
Special  attention  is  given  to  relieving  farm  life  of  its  drudgery  by  applying  power  to  the 
disagreeable  small  tasks  which  must  otherwise  be  done  by  hand.  Many  homemade  con- 
trivances for  cutting  wood,  supplying  kitchen:  garden  and  barn  with  water,  loading,  hauling 
and  unloading  hay.  delivering  grain  to  the  bins  or  the  feed  trough  are  included;  also  full 
directions  for  making  the  engine  milk  the  cows,  churn,  wash,  sweep  the  house  and  clean  the 
windows,  etc.  Very  fully  illustrated  with  drawings  of  working  parts  and  cuts  showing 
Stationary.  Portable  and  Tractor  Engines  doing  all  kinds  of  farm  work.  300  pages.  Nearly 
150  engravings.     12mo.    Price $1.50 

CHEMISTRY   OF   GAS   MANUFACTURE.     By  H.  M.  Royles. 

This  book  covers  points  likely  to  arise  in  the  ordinary  course  of  the  duties  of  the  engineer  or 
manager  of  a  gas  works  not  large  enough  to  necessitate  the  employment  of  a  separate  chemical 
staff.  It  treats  of  the  testing  of  the  raw  materials  employed  in  the  manufacture  of  illuminat- 
ing coal  gas,  and  of  the  gas  produced.  The  preparation  of  standard  solutions  is  given  as  well 
as  the  chemical  and  physical  examination  of  gas  coal  including  among  its  contents — Prepa- 
rations of  Standard  Solutions,  Coal,  Furnaces,  Testing  and  Regulation.  Products  of  Car- 
bonization. Analysis  of  Crude  Coal  Gas.  Analysis  of  Lime.  Ammonia.  Analysis  of  Oxide 
of  Iron.  Naphthalene.  Analysis  of  Fire-Bricks  and  Fire-Clay.  Weldom  and  Spent  Oxide. 
Photometry  and  Gas  Testing.  Carburetted  Water  Gas.  Metropolis  Gas.  Miscellaneous 
Extracts.     Useful  Tables $4.50 

GEARING  AND   CAMS 

BEVEL   GEAR   TABLES.     By  D.  Ac.  Engstrom. 

A  book  that  will  at  once  commend  itself  to  mechanics  and  draftsmen.  Does  away  with  all 
the  trigonometry  and  fancy  figuring  on  bevel  gears  and  makes  it  easy  for  anyone  to  lay  them 
out  or  make  them  just  right.  There  are  36  full-page  tables  that  show  every  necessary  dimen- 
sion for  all  sizes  or  combinations  you're  apt  to  need.  No  puzzling  figuring  or  guessing. 
Gives  placing  distance,  all  the  angles  (including  cutting  angles),  and  the  correct  cutter  to  use. 
A  copy  of   this   prepares    you  for   anything   in  the    bevel  gear  line.     66   pages.     .     $1.00 

CHANGE   GEAR   DEVICES.     By  Oscar  E.  Perrigo. 

A  practical  book  for  every  designer,  draftsman,  and  mechanic  interested  in  the  invention  and 
development  of  the  devices  formfeed  changes  on  the  different  machines  requiring  such  mechan- 
ism. All  the  necessary  information  on  this  subject  is  taken  up,  analyzed,  classified,  sifted, 
and  concentrated  for  the  use  of  busy  men  who  have  not  the  time  to  go  through  the  masses 
of  irrelevant  matter  with  which  such  a  subject  is  usually  encumbered  and  select  such  infor- 
mation as  will  be  useful  to  them. 

It  shows  just  what  has  been  done,  how  it  has  been  done,  when  it  was  done,  and  who  did  it. 
It  saves  time  in  hunting  up  patent  records  and  re-inventing  old   ideas.     88  pages.     $1.00 

14 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

DRAFTING  OF  CAMS.     By  Louis  Rotjillion. 

The  laying  out  of  cams  is  a  serious  problem  unless  you  know  how  to  go  at  it  right.  This  puts 
you  on  the  right  road  for  practically  any  kind  of  cam  you  are  likely  to  run  up  against.  25  cents 

HYDRAULICS 

HYDRAULIC   ENGINEERING.     By  Gardner  D.  Hiscox. 

A  treatise  on  the  properties,  power,  and  resources  of  water  for  all  purposes.  Including  the 
measurement  of  streams,  the  flow  of  water  in  pipes  or  conduits;  the  horse-power  of  falling 
water;  turbine  and  impact  water-wheels,  wave  motors,  centrifugal,  reciprocating,  and  air- 
lift pumps.    With  300  figures  and  diagrams  and  36  practical  tables. 

All  who  are  interested  in  water-works  development  will  find  this  book  a  useful  one,  because 
it  is  an  entirely  practical  treatise  upon  a  subject  of  present  importance,  and  cannot  fail  in 
having  a  far-reaching  influence,  and  for  this  reason  should  have  a  place  in  the  working  library 
of  every  engineer.  Among  the  subjects  treated  are:  Historical — Hydraulics,  Properties  of 
Water;  Measurement  of  the  flow  of  Streams;  Flow  from  Subsurface  orifices  and  nozzles; 
Flow  of  water  in  Pipes;  Siphons  of  various  kinds;  Dams  and  Great  Storage  Reservoirs; 
City  and  Town  Water  Supply;  Wells  and  their  reenforcement ;  Air  lift  methods  of  raising 
water:  artesian  wells;  Irrigation  of  Arid  districts:  Water  Power.  Water  Wheels;  Pumps  and 
Pumping  Machinery;  Reciprocating  Pumps;  Hydraulic  Power  Transmission;  Hydraulic 
Mining;  Canals;  Ditches:  Conduits  and  Pipe  Lines;  Marine  Hydraulics;  Tidal  and  Sea 
Wave  power,  etc.  320  pages.  Price $4.00 

ICE    AND    REFRIGERATION 

POCKET  BOOK  OF  REFRIGERATION  AND  ICE  MAKING.  By  A.  J.  Wallis- 
Taylor. 

This  is  one  of  the  latest  and  most  comprehensive  reference  books  published  on  the  subject  of 
refrigeration  and  cold  storage.  It  explains  the  properties  and  refrigerating  effect  of  the  different 
fluids  in  use,  the  management  of  refrigerating  machinery  and  the  construction  and  insulation 
of  cold  rooms  with  their  required  pipe  surface  for  different  degrees  of  cold;  freezing  mixtures 
and  non-freezing  brines,  temperatures  of  cold  rooms  for  all  kinds  of  provisions,  cold  storage 
charges  for  all  classes  of  goods,  ice  making  and  storage  of  ice,  data  and  memoranda  for  constant 
reference  by  refrigerating  engineers,  with  nearly  one  hundred  tables  containing  valuable 
references  to  every  fact  and  condition  required  in  the  installment  and  operation  of  a  refrigerat- 
ing plant.     Illustrated.    (5th  Edition,  revised.)     Price $1.50 

INVENTIONS— PATENTS 

INVENTOR'S  MANUAL,  HOW  TO  MAKE  A  PATENT  PAY. 

This  is  a  book  designed  as  a  guide  to  inventors  in  perfecting  their  inventions,  taking  out  their 
patents  and  disposing  of  them.  It  is  not  in  any  sense  a  Patent  Solicitor's  Circular,  nor  a 
Patent  Broker's  Advertisement.  No  advertisements  of  any  description  appear  in  the  work. 
It  is  a  book  containing  a  quarter  of  a  century's  experience  of  a  successful  inventor,  together 
with  notes  based  upon  the  experience  of  many  other  inventors. 

Among  the  subjects  treated  in  this  work  are:  How  to  Invent.  How  to  Secure  a  Good 
Patent.  Value  of  Good  Invention.  How  to  exhibit  an  Invention.  How  to  Interest 
Capital.  How  to  Estimate  the  Value  of  a  Patent.  Value  of  Design  Patents.  Value  of 
Foreign  Patents.  Value  of  Small  Inventions.  Advice  on  Selling  Patents.  Advice  on  the 
Formation  of  Stock  Companies.  Advice  on  the  Formation  of  Limited  Liability  Companies. 
Advice  on  Disposing  of  Old  Patents.  Advice  as  to  Patent  Attorneys.  Advice  as  to  Selling 
Agents.  Forms  of  Assignments.  License  and  Contracts.  State  Laws  Concerning  Patent 
Rights.  1900  Census  of  the  United  States  by  counties  of  over  10,000  population.  Revised 
editurn.      120  pages.     Price $1.00 

KNOTS 

KNOTS,  SPLICES  AND  ROPE  WORK.     By  A.  Hyatt  Verrill. 

This  is  a  practical  book  giving  complete  and  simple  directions  for  making  all  the  most  use- 
ful and  ornamental  knots  in  common  use.  with  chapters  on  Splicing,   Pointing,    Seizing, 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

Serving,  etc.  This  book  is  fully  illustrated  with  one  hundred  and  fifty  original  engravings, 
which  show  how  each  knot,  tie  or  splice  is  formed  and  its  appearance  when  finished.  The 
book  will  be  found  of  the  greatest  value  to  Campers,  Yachtsmen,  Travelers,  Boy  Scouts, 
in  fact  to  anyone  having  occasion  to  use  or  handle  rope  or  knots  for  any  purpose.  The  book 
is  thoroughly  reliable  and  practical  and  is  not  only  a  guide  but  a  teacher.  It  is  the  standard 
work  on  the  subject.  Among  the  contents  are:  1.  Cordage,  Kinds  of  Rope.  Construction 
of  Rope,  Parts  of  Rope  Cable  and  Bolt  Rope.  Strength  of  Rope,  Weight  of  Rope.  2.  Sim- 
ple knots  and  Bends.  Terms  used  in  Handling  Rope.  Seizing  Rope.  3.  Ties  and  Hitches. 
4.  Noose.  Loops  and  Mooring  Knots.  5.  Shortenings.  Grommets  and  Selvages.  6.  Lash- 
ings. Seizings  and  Splices.  7.  Fancy  Knots  and  Rope  Work.  128  pages.  150  original 
engravings.     Price 60  cents 

LATHE   WORK 

MODERN  AMERICAN  LATHE  PRACTICE.     By  Oscar  E.  Perrigo. 

This  is  a  new  book  from  cover  to  cover,  and  the  only  complete  American  work  on  the  subject 
written  by  a  man  who  knows  not  only  how  work  ought  to  be  done,  but  who  also  knows 
how  to  do  it,  and  how  to  convey  this  knowledge  to  others.  It  is  strictly  up-to-date  in  its 
descriptions  and  illustrations,  which  represent  the  very  latest  practice  in  lathe  and  boring 
mill  operations  as  well  as  the  construction  of  and  latest  developments  in  the  manufacture 
of  these  important  classes  of  machine  tools. 

Lathe  history  and  the  relations  of  the  Lathe  to  manufacturing  are  given;  also  a  description 
of  the  various  devices  for  Feeds  and  Thread  Cutting  mechanisms  from  early  efforts  in  this 
direction  to  the  present  time.  Lathe  design  is  thoroughly  discussed,  including  Back  Gearing, 
Driving  Cones,  Thread  Cutting  Gears,  and  all  the  essential  elements  of  the  modern  Lathe. 
The  classification  of  Lathes  is  taken  up,  giving  the  essential  differences  of  the  several  types 
of  Lathes,  including,  as  is  usually  understood,  Engine  Lathes.  Bench  Lathes,  Speed  Lathes, 
Forge  Lathes,  Gap  Lathes,  Pulley  Lathes,  Forming  Lathes,  Multiple  Spindle  Lathes,  Rapid 
Reduction  Lathes,  Precision  Lathes,  Turret  Lathes,  Special  Lathes,  Electrically  Driven 
Lathes,  etc.    424  pages.    314  illustrations.    Price ......     $2.50 

PRACTICAL   METAL   TURNING.     By  Joseph  G.  Horner. 

This  important  and  practical  subject  is  treated  in  a  full  and  exhaustive  manner  and  nothing 
of  importance  is  omitted.  The  principles  and  practice  and  all  the  different  branches  of  Turn- 
ing are  considered  and  well  illustrated.  All  the  different  kinds  of  Chucks  of  usual  forms,  as 
well  as  some  unusual  kinds,  are  shown.  A  feature  of  the  book  is  the  important  section  de- 
voted to  modern  Turret  practice;  Boring  is  another  subject  which  is  treated  fully;  and  the 
chapter  on  Tool  Holders  illustrates  a  large  number  of  representative  types.  Thread  Cutting 
is  treated  at  reasonable  length;  and  the  last  chapter  contains  a  good  deal  of  information 
relating  to  the  High-Speed  Steels  and  their  work.  The  numerous  tools  used  by  machinists 
are  illustrated,  and  also  the  aujuncts  of  the  lathe.  In  fact,  the  entire  subject  is  treated  in 
such  a  thorough  manner  as  to  make  this  book  the  standard  one  on  ihe  subject.  It  is  indis- 
pensable to  the  manager,  engineer,  and  machinist  as  well  as  to  the  student,  amateur,  and 
experimental,  man  who  desires  to  keep  up-to-date.     400  pages,  fully  illustiated.    Price     $3.50 

TURNING  AND  BORING  TAPERS.     By  Fred  H.  Colvin. 

There  are  two  ways  to  turn  tapers;  the  right  way  and  one  other.  This  treatise  has  to  do  with 
the  right  way;  it  tells  you  how  to  start  the  work  properly,  how  to  set  the  lathe,  what  tools  to 
use  and  how  to  use  them,  and  forty  and  one  other  little  things  that  y  >u  should  know.  Fourth 
edition 25  cent9 


LIQUID  AIR 


LIQUID  AIR  AND  THE  LIQUEFACTION  OF  GASES.     By  T.  O'Conor  Sloane. 

This  book    gives  the  history  of  the  theory,  discovery,  and  manufacture  of  Liquid  Air,  and 

contains   an  illustrated  description  of  all  the  experiments  that  have  excited  the  wonder  of 

audiences   all  over  the  country.     It  shows  how  liquid  air,  like  water,  is  carried  hundreds  of 

miles  and  is   handled  in  open  buckets.     It  tells  what  may  be  expected  from  it  in  the  near 

future. 

A  book   that  renders  simple  one  of  the  most  perplexing  chemical  problems  of  the  century. 

Startling  developments  illustrated  by  actual  experiments. 

It  is  not  only  a  work  of  scientific  interest  and  authority,  but  is  intended  for  the  general  reader, 

oeing  written    in  a  popular  style — easily  understood  by  every  one.     Second  edition.     365 

pages.     Price        $2.00 

16 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
LOCOMOTIVE  ENGINEERING 

AIR-BRAKE    CATECHISM.     By  Robert  H.  Blackall. 

This  book  is  a  standard  text  book.  It  covers  the  Westinghouse  Air-Brake  Equipment,  in- 
cluding the  No.  5  and  the  No.  6  E.  T  Locomotive  Brake  Equipment;  the  K  (Quick-Service) 
Triple  Valve  for  Freight  Service;  and  the  Cross-Compound  Pump.  The  operation  of  all  parts 
of  the  apparatus  is  explained  in  detail,  and  a  practical  way  of  finding  their  peculiarities  and 
defects,  with  a  proper  remedy,  is  given.  It  contains  2,000  questions  with  their  answers, 
which  will  enable  any  railroad  man  to  pass  any  examination  on  the  subject  of  Air  Brakes. 
Endorsed  and  used  by  air-brake  instructors  and  examiners  on  nearly  every  railroad  in  the 
United  States.  25th  Edition.  350  pages,  fully  illustrated  with  folding  plates  and  dia- 
grams  $2.00 

AMERICAN    COMPOUND    LOCOMOTIVES.     By  Fred.  H.  Colvin. 

The  only  book  on  compounds  for  the  engineman  or  shopman  that  shows  in  a  plain,  practical 
way  the  various  features  of  compound  locomotives  in  use.  Shows  how  they  are  made,  what 
to  do  when  they  break  down  or  balk.  Contains  sections  as  follows: — A  Bit  of  History.  The- 
ory of  Compounding  Steam  Cylinders.  Baldwin  Two-Cylinder  Compound.  Pittsburg  Two- 
Cylinder  Compound.  Rhode  Island  Compound.  Richmond  Compound.  Rogers  Compound. 
Schenectady  Two-Cylinder  Compound.  Vauclain  Compound.  Tandem  Compounds.  Bald- 
win Tandem.  The  Colvin- Wight  man  Tandem.  Schenectady  Tandem.  Balanced  Loco- 
motives. Baldwin  Balanced  Compound.  Plans  for  Balancing.  Locating  Blows.  Break- 
downs. Reducing  Valves.  Drifting.  Valve  Motion.  Disconnecting.  Power  of  Compound 
Locomotives.     Practical  Notes. 

Fully  illustrated  'and  containing  ten  special  "Duotone"  inserts  on  heavy  Plate  Paper,  show- 
ing different  types  of  Compounds.      142  pages.     Price $1.00 

APPLICATION  OF  HIGHLY  SUPERHEATED  STEAM   TO  LOCOMOTIVES.     By 

Robert  Garbe. 

A  practical  book.  Contains  special  chapters  on  Generation  of  Highly  Superheated  Steam; 
Superheated  Steam  and  the  Two-Cylinder  Simple  Engine;  Compounding  and  Superheating; 
Designs  ofj  Locomotive  Superheaters;  Constructive  Details  of  Locomotives  using  Highly 
Superheated  Steam;  Experimental  and  Working  Results.  Illustrated  with  folding  plates 
and  tables.     Price $2.50 

COMBUSTION  OF  COAL  AND  THE  PREVENTION  OF  SMOKE. 
By  Wm.  M.  Barr. 

This  book  has  been  prepared  with  special  reference  to  the  generation  of  heat  by  the  combus- 
tion of  the  common  fuels  found  in  the  United  States,  and  deals  particularly  with  the  condi- 
tions necessary  to  the  economic  and  smokeless  combustion  of  bituminous  coal  in  Stationary 
and  Locomotive  Steam  Boilers. 

The  presentation  of  this  important  subject  is  systematic  and  progressive.  The  arrangement 
of  the  book  is  in  a  series  of  practical  questions  to  which  are  appended  accurate  answers, 
which  describe  in  language,  free  from  technicalities,  the  several  processes  involved  in  the 
furnace  combustion  of  American  fuels;  it  clearly  states  the  essential  requisites  for  perfect 
combustion,  and  points  out  the  best  methods  of  furnace  construction  for  obtaining  the 
greatest  quantity  of  heat  from  any  given  quality  of  coal.  Nearly  350  pages,  fully  illustrated. 
Price $1.00 

DIARY  OF  A  ROUND  HOUSE  FOREMAN.     By  T.  S.  Reilly     . 

This  is  the  greatest  book  of  railroad  experiences  ever  published.  Containing  a  fund  of  infor- 
mation and  suggestions  along  the  line  of  handling  men,  organizing,  etc.,  that  one  cannot  afford 
to  miss.     176  pages.     Price $1.00 

LINK  MOTIONS,  VALVES  AND  VALVE  SETTING.  By  Fred  H.  Colvin,  Associate 
Editor  of  "American  Machinist." 

A  handy  book  for  the  engineer  or  machinist  that  clears  up  the  mysteries  of  valve  setting. 
Shows  the  different  valve  gears  in  use,  how  they  work,  and  why.  Piston  and  slide  valves 
of  different  types  are  illustrated  and  explained.  A  book  that  every  railroad  man  in  the  mo- 
tive power  department  ought  to  have.  Contains  chapters  on  Locomotive  Link  Motion, 
Valve  Movements,  Setting  Slide  Valves,  Analysis  by  Diagrams,  Modern  Practice,  Slip  of 
Block,  Slide  Valves,  Piston  Valves,  Setting  Piston  Valves,  Joy-Allen  Valve  Gear,  Walschaert 
Valve  Gear,  Gooch  Valve  Gear,  Alfree-Hubbell  Valve  Gear,  etc.,  etc.  Fully  illustrated. 
Price        .     .     . 50  cents 

17 


CATALOGUE  OF   GOOD,  PRACTICAL  BOOKS 

LOCOMOTIVE   BOILER   CONSTRUCTION.     By  Frank  A.  Kleinhans. 

The  construction  of  boilers  in  general  is  treated,  and  following  this,  the  locomotive  boiler 
is  taken  up  in  the  order  in  which  its  various  parts  go  through  the  shop.  Shows  all  types  of 
boilers  used;  gives  details  of  construction;  practical  facts,  such  as  life  of  riveting,  punches 
and  dies;  work  done  per  day,  allowance  for  bending  and  flanging  sheets,  and  other  data. 
Locomotive  boilers  present  more  difficulty  in  laying  out  and  building  than  any  other  type, 
and  for  this  reason  the  author  uses  them  as  examples.  Anyone  who.  can  handle  them  can 
tackle  anything. 

Contains  chapters  on  Laying  Out  Work;  Flanging  and  Forging;  Punching;  Shearing;  Plate 
Planing;  General  Tables;  Finishing  Parts;  Bending;  Machinery  Parts;  Riveting;  Boiler 
Details;  Smoke  Box  Details;  Assembling  and  Calking;  Boiler  Shop  Machinery,  etc.,  etc. 
There  isn't  a  man  who  has  anything  to  do  with  boiler  work,  either  new  or  repair  work,  who 
doesn't  need  this  book.  The  manufacturer,  superintendent,  foreman,  and  boiler  worker — 
all  need  it.  No  matter  what  the  type  of  boiler,  you'll  find  a  mint  of  information  that  you 
wouldn't  be  without.      Over  400  pages,  five  large  folding  plates.     Price $3.00 

LOCOMOTIVE  BREAKDOWNS  AND  THEIR  REMEDIES.  By  Geo.  L.  Fowler. 
Revised  by  Wm.  W.  Wood,  Air-Brake  Instructor.  Just  issued.  Revised  pocket 
edition. 

It  is  out  of  the  question  to  try  and  tell  you  about  every  subject  that  is  covered  in  this  pocket 
edition  of  Locomotive  Breakdowns.  Just  imagine  all  the  common  troubles  that  an  engineer 
may  expect  to  happen  some  time,  and  then  add  all  of  the  unexpected  ones,  troubles  that  could 
occur,  but  that  you  had  never  thought  about,  and  you  will  find  that  they  are  all  treated  with 
the  very  best  methods  of  repair.  Walschaert  Locomotive  Valve  Gear  Troubles,  Electric 
Headlight  Troubles,  as  well  as  Questions  and  Answers  on  the  Air  Brake  are  all  included.  294 
pages.      7th  Revised  Edition.     Fully  illustrated $1.00 

LOCOMOTIVE   CATECHISM.     By  Robert  Grimshaw. 

The  revised  edition  of  "Locomotive  Catechism,"  by  Robert  Grimshaw,  is  a  New  Book  from 
Cover  to  Cover.  It  contains  twice  as  many  pages  and  double  the  number  of  illustrations 
of  previous  editions.  Includes  the  greatest  amount  of  practical  information  ever  published 
on  the  construction  and  management  of  modern  locomotives.  Specially  Prepared  Chapters 
on  the  Walschaert  Locomotive  Valve  Gear,  the  Air  Brake  Equipment  and  the  Electric  Head 
Light  are  given. 

It  commends  itself  at  once  to  every  Engineer  and  Fireman,  and  to  all  who  are  going  in  for 
examination  or  promotion.  In  plain  language,  with  full  complete  answers,  not  only  all  the 
questions  asked  by  the  examining  engineer  are  given,  but  those  which  the  young  and  less 
experienced  would  ask  the  veteran,  and  which  old  hands  ask  as  "stickers."  It  is  a  veritable 
Encyclopedia  of  the  Locomotive,  is  entirely  free  from  mathematics,  easily  understood  and 
thoroughly  up-to-date.  Contains  over  4,000  Examination  Questions  with  their  Answers. 
825  pages,  437  illustrations  and  three  folding  plates.     28th  Revised  Edition.     .      .     $2.50 

PRACTICAL  INSTRUCTOR  AND  REFERENCE  BOOK  FOR  LOCOMOTIVE 
FIREMEN  AND  ENGINEERS.     By  Chas.  F.  Lockhart. 

An  entirely  new  book  on  the  Locomotive.  It  appeals  to  every  railroad  man,  as  it  tells  him 
how  things  are  done  and  the  right  way  to  do  them.  Written  by  a  man  who  has  had  years 
of  practical  experience  in  locomotive  shops  and  on  the  road  firing  and  running.  The  infor- 
mation given  in  this  book  cannot  be  found  in  any  other  similar  treatise.  Eight  hundred  and 
fifty-one  questions  with  their  answers  are  included,  which  will  prove  specially  helpful  to 
those  preparing  for  examination.  Practical  information  on:  The  Construction  and  Opera- 
tion of  Locomotives.  Breakdowns  and  their  Remedies;  Air  Brakes  and  Valve  Gears. 
Rules  and  Signals  are  handled  in  a  thorough  manner.  As  a  book  of  reference  it  cannot  be 
excelled.  The  book  is  divided  into  six  parts,  as  follows:  1.  The  Fireman's  Duties.  2. 
General  description  of  the  Locomotive.  3.  Breakdowns  and  their  Remedies.  4.  Air  Brakes. 
5.  Extracts  from  Standard  Rules.  6.  Questions  for  examination.  The  851  questions  have 
been  carefully  selected  and  arranged.  These  cover  the  examinations  required  by  the  different 
railroads.     368  pages.    88  illustrations.     Price $1.50 

PREVENTION  OF  RAILROAD  ACCIDENTS,  OR  SAFETY  IN  RAILROADING. 

By  George  Bradshaw. 

This  book  is  a  heart-to-heart  talk  with  Railroad  Employees,  dealing  with  facts,  not  theories, 
and  showing  the  men  in  the  ranks,  from  every-day  experience,  how  accidents  occur  and  how 
they  may  be  avoided.  The  book  is  illustrated  with  seventy  original  photographs  and  draw- 
ings showing  the  safe  and  unsafe  methods  of  work.  No  visionary  schemes,  no  ideal  pictures. 
Just  plain  facts  and  Practical  Suggestions  are  given.    Every  railroad  employee  who  reads  the 

18 


CATALOGUE   OF   GOOD,  PRACTICAL  BOOKS 

book  is  a  better  and  safer  man  to  have  in  railroad  service.  It  gives  just  the  information 
which  will  be  the  means  of  preventing  many  injuries  and  deaths.  All  railroad  employees 
should  procure  a  copy,  read  it.  and  do  your  part  in  preventing  accidents.  169  pages.  Pocket 
Size.     Fully  illustrated.     Price 50  cents 

TRAIN  RULE  EXAMINATIONS  MADE  EASY.     By  G.  E.  Colling  wood. 

This  is  the  only  practical  work  on  train-rules  in  print.  Every  detail  is  covered,  and  puzzling 
points  are  explained  in  simple,  comprehensive  language,  making  it  a  practical  treatise  for 
the  Train  Dispatcher,  Engineman.  Trainman,  and  all  others  who  ha'e  to  do  with  the  move- 
ments of  trains.  Contains  complete  and  reliable  information  of  the  Standard  Code  of  Train 
Rules  for  single  track.  Shows  Signals  in  Colors,  as  used  on  the  different  roads.  Explains 
fully  the  practical  application  of  train  orders,  giving  a  clear  and  definite  understanding  of  all 
orders  which  may  be  used.  The  meaning  and  necessity  for  certain  rules  are  explained  in 
such  a  manner  that  the  student  may  know  beyond  a  doubt  the  rights  conferred  under  any 
orders  he  may  receive  or  the  action  required  by  certain  rules. 

As  nearly  all  roads  require  trainmen  to  pass  regular  examinations,  a  complete  set  of  examina- 
tion questions,  with  their  answers,  are  included.  These  will  enable  the  student  to  pass  the 
required  examinations  with  credit  to  himself  and  the  road  for  which  he  works.  256  pages.. 
Fully  illustrated  with  Train  Signals  in  colors.     Price $1.26 

TRAIN-  RULES    AND    DESPATCHING.     By  H.  A.  Dalby. 

Every  railroad  man,  no  matter  what  department  he's  in,  needs  a  copy  of  this  book.  It  gives, 
the  standard  rules  for  both  single  and  double  track,  shows  all  the  signals,  with  colors  wher- 
ever necessary,  and  has  a  list  of  towns  where  time  changes,  with  a  map  showing  the  whole 
country.  The  rules  are  explained  wherever  there  is  any  doubt  about  their  meaning  or  where 
they  are  modified  by  different  railroads.  It's  the  only  practical  book  on  train  rules  in  print. 
Over  220  pages.     Leather  cover.      Price $1.50 

THE  WALSCHAERT  AND  OTHER  MODERN  RADIAL  VALVE  GEARS  FOR 
LOCOMOTIVES.     By  Wm.  W.  Wood. 

If  you  would  thoroughly  understand  the  Walschaert  Valve  Gear  you  should  possess  a  copy 
of  this  book,  as  the  author  takes  the  plainest  form  of  a  steam  engine — a  stationary  engine  in 
the  rough,  that  will  only  turn  its  crank  in  one  direction — and  from  it  builds  up — with  the 
reader's  help — a  modern  locomotive  equipped  with  the  Walschaert  Valve  Gear,  complete. 
The  points  discussed  are  clearly  illustrated:  two  large  folding  plates  that  show  the  positions 
of  the  valves  of  both  inside  or  outside  admission  type,  as  well  as  the  links  and  other  parts  of 
the  gear  when  the  crank  is  at  nine  different  points  in  its  revolution,  are  especially  valuable 
in  making  the  movement  clear.  These  employ  sliding  cardboard  models  which  are  contained 
in  a  pocket  in  the  cover. 

The  book  is  divided  into  five  general  divisions,  as  follows:  I.  Analysis  of  the  gear.  II.  De- 
signing and  erecting  the  gear.  III.  Advantages  of  the  gear.  IV.  Questions  and  answers 
relating  to  the  Walschaert  Valve  Gear.  V.  Setting  valves  with  the  Walschaert  Valve  Gear; 
the  three  primary  types  of  locomotive  valve  motion;  modern  radial  valve  gears  other  than 
the  Walschaert;  the  Hobart  All-free  valve  and  valve  gear,  with  questions  and  answers  on 
breakdowns:  the  Baker-Pilliocl  valve  gear;  the  Improved  Baker-Pilliod  Valve  Gear,  with 
questions  and  answers  on  breakdowns. 

The  questions  with  full  answers  given  will  be  especially  valuable  to  firemen  and  engineers 
in  preparing  for  an  examination  for  promotion.  24.5  pages.  Third  Revised  Edition. 
-price $1.50 

WESTINGHOUSE  E— T  AIR-BRAKE  INSTRUCTION  POCKET  BOOK.  By  Wm. 
W.  Wood,  Air-Brake  Instructor. 

Here  is  a  book  for  the  railroad  man,  and  the  man  who  aims  to  be  one.  It  is  without  doubt 
the  only  complete  work  published  on  the  Westinghouse  E-T  Locomotive  Brake  Equipment. 
Written  by  an  Air  Brake  Instructor  who  knows  just  what  is  needed.  It  covers  the  subject 
thoroughly.  Everything  about  the  New  Westinghouse  Engine  and  Tender  Brake  Equip- 
ment, including  the  Standard  No.  5  and  the  Perfected  No.  6  Style  of  brake,  is  treated  in  de- 
tail. W  ritten  in  plain  English  and  profusely  illustrated  with  Colored  Plates,  which  enable 
one  to  trace  the  flow  of  pressures  throughout  the  entire  equipment.  The  best  book  ever 
published  on  the  Air  Brake.  Equally  good  for  the  beginner  and  the  advanced  engineer. 
\\  ill  pass  any  one  through  any  examination.  It  informs  and  enlightens  you  on  every  point. 
Indispensable  to  every  engineman  and  trainman. 

Contains  examination  questions  and  answers  on  the  E-T  equipment.  Covering  what  the 
E-T  Brake  is.  How  it  should  be  operated.  What  to  do  when  defective.  Not  a  question  can 
be  asked  of  the  engineman  up  for  promotion  on  either  the  No.  5  or  the  No.  6  E-T  equipment 
that  is  not  asked  and  answered  in  the  book.  If  you  want  to  thoroughly  understand  the  E-T 
equipment  get  a  copy  of  this  book.  It  covers  every  detail.  Makes  Air  Brake  troubles  and 
examinations  easy.     Price $1.60 

«9 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
MACHINE   SHOP  PRACTICE 

AMERICAN  TOOL  MAKING  AND  INTERCHANGEABLE  MANUFACTURING.     By 

J.    V.    WOODWOHTH. 

A  "shoppy"  book,  containing  no  theorizing,  no  problematical  or  experimental  devices,  there 
are  no  badly  proportioned  and  impossible  diagrams,  no  catalogue  cuts,  but  a  valuable  collec- 
tion of  drawings  and  descriptions  of  devices,  the  rich  fruits  of  the  author's  own  experience. 
In  its  500-odd  pages  the  one  subject  only,  Tool  Making,  and  whatever  relates  thereto,  is 
dealt  with.  The  work  stands  without  a  rival.  It  is  a  complete  practical  treatise  on  the 
art  of  American  Tool  Making  and  system  of  interchangeable  manufacturing  as  carried  on 
to-day  in  the  United  States.  In  it  are  described  and  illustrated  all  of  the  different  types 
and  classes  of  small  tools,  fixtures,  devices,  and  special  appliances  which  are  in  general  use 
in  all  machine  manufacturing  and  metal  working  establishments  where  economy,  capacity, 
and  interchangeability  in  the  production  of  machined  metal  parts  are  imperative.  The 
science  of  jig  making  is  exhaustively  discussed,  and  particular  attention  is  paid  to  drill  jigs, 
boring,  profiling  and  milling  fixtures  and  other  devices  in  which  the  parts  to  be  machined 
are  located  and  fastened  within  the  contrivances.  All  of  the  tools,  fixtures,  and  devices 
illustrated  and  described  have  been  or  are  used  for  the  actual  production  of  work,  such  as 
parts  of  drill  presses,  lathes,  patented  machinery,  typewriters,  electrical  apparatus,  mechan- 
ical appliances,  brass  goods,  composition  parts,  mould  products,  sheet  metal  articles,  drop 
forgings,  jewelry,  watches,  medals,  coins,  etc.    531  pages.    Price $4.00 

HENLEY'S  ENCYCLOPEDIA    OF    PRACTICAL    ENGINEERING    AND     ALLIED 

TRADES.     Edited  by  Joseph  G.  Horner,  A.M. I.,  M.E. 

This  set  of  five  volumes  contains  about  2,500  pages  with  thousands  of  illustrations,  including 
diagrammatic  and  sectional  drawings  with  full  explanatory  details.  This  work  covers  the 
entire  practice  of  Civil  and  Mechanical  Engineering.  The  best  known  expert  in  all  branches 
of  engineering  have  contributed  to  these  volumes.  The  Cyclopedia  is  admirably  well  adapted 
to  the  needs  of  the  beginner  and  the  self-taught  practical  man,  as  well  as  the  mechanical  en- 
gineer, designer,  draftsman,  shop  superintendent,  foreman,  and  machinist.  The  work  will  be 
found  a  means  of  advancement  to  any  progressive  man.  It  is  encyclopedic  in  scope,  thorough 
and  practical  in  its  treatment  of  technical  subjects,  simple  and  clear  in  its  descriptive  matter, 
and  without  unnecessary  technicalities  or  formulae.  The  articles  are  as  brief  as  may  be  and 
yet  give  a  reasonably  clear  and  explicit  statement  of  the  subject,  and  are  written  by  men  who 
have  had  ample  practical  experience  in  the  matters  of  which  they  write.  It  tells  you  all  you 
want  to  know  about  engineering  and  tells  it  so  simply,  so  clearly,  so  concisely,  that  one  cannot 
help  but  understand.  As  a  work  of  reference  it  is  without  a  peer.  $6.00  per  volume.  For 
complete  set  of  five  volumes,  price $25.00 

MACHINE  SHOP  ARITHMETIC.     By  Colvin-Cheney. 

This  is  an  arithmetic  of  the  things  you  have  to  do  with  daily.  It  tells  you  plainly  about:  how 
to  find  areas  of  figures;  how  to  find  surface  or  volume  of  balls  or  spheres;  handy  ways  for 
calculating;  about  compound  gearing;  cutting  screw  threads  on  any  lathe;  drilling  for  taps; 
speeds  of  drills,  taps,  emery  wheels,  grindstones,  milling  cutters,  etc.;  all  about  the  Metric 
system  with  conversion  tables;  properties  of  metals;  strength  of  bolts  and  nuts;  decimal 
equivalent  of  an  inch.  All  sorts  of  machine  shop  figuring  and  1,001  other  things,  any  one  of 
Y/hich  ought  to  be  worth  more  than  the  price  of  this  book  to  you,  and  it  saves  you  the  trouble 
of  bothering  the  boss.      6th  Edition.     131  pages.     Price 50  cents 

MODERN  MACHINE  SHOP  CONSTRUCTION,  EQUIPMENT  AND  MANAGEMENT. 

By  Oscar  E.  Perrigo. 

The  only  work  published  that  describes  the  Modern  Machine  Shop  or  Manufacturing  Plant  from 
the  time  the  grass  is  growing  on  the  site  intended  for  it  until  the  finished  product  is  shipped. 
Just  the  book  needed  by  those  contemplating  the  erection  of  modern  shop  buildings,  the  re- 
building and  reorganization  of  old  ones,  or  the  introduction  of  Modern  Shop  Methods,  time  and 
cost  systems.  It  is  a  book  written  and  illustrated  by  a  practical  shop  man  for  practical  shop 
men  who  are  too  busy  to  read  theories  and  want  facts.  It  is  the  most  complete  all-around 
book  of  its  kind  ever  published.  400  large  quarto  pages.  225  original  and  specially-made 
illustrations.      Price $5.00 

MECHANICAL    APPLIANCES,  MECHANICAL    MOVEMENTS  AND    NOVELTIES 

OF  CONSTRUCTION.     By  Gardner  D.  Hiscox. 

This  is  a  supplementary  volume  to  the  one  jpon  mechanical  movements.  Unlike  the  first 
volume,  which  is  more  elementary  in  character,  this  volume  contains  illustrations  and  descrip- 
tions of  many  combinations  of  motions  and  of  mechanical  devices  and  appliances  found  in 
different  lines  of  machinery.      Each  device  being  shown  bv  a  line  drawing  with  a  description 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


showing  its  working  parts  and  the  method  of  operation.  From  the  multitude  of  devices  de- 
scribed, and  illustrated,  might  be  mentioned,  in  passing,  such  items  as  conveyors  and  elevators, 
Prony  brakes,  thermometers,)  various  types  of  boilers,  solar  engines,  oil-fuel  burners,  condensers, 
evaporators,  Corliss  and  other  valve  gears,  governors,  gas  engines,  water  motors  of  various 
descriptions,  air  ships,  motors  and  dynamos,  automobile  and  motor  bicycles,  railway  block 
signals,  car  couplers,  link  and  gear  motions,  ball  bearings,  breech  block  mechanism  for  heavy 
guns,  and  a  large  accumulation  of  others  of  equal  importance.  1,000  specially  made  engrav- 
ings.    396  octavo  pages.     Price  $2.50 

MECHANICAL  MOVEMENTS,  POWERS,  AND  DEVICES.     By  Gardner  D.  Hiscox. 

This  is  a  collection  of  1,890  engravings  of  different  mechanical  motions  and  appliances,  accom- 
panied by  appropriate  text,  making  it  a  book  of  great  value  to  the  inventor,  the  draftsman, 
and  to  all  readers  with  mechanical  tastes.  The  book  is  divided  into  eighteen  sections  or 
chapters  in  which  the  subject  matter  is  classified  under  the  following  heads:  Mechanical  Powers; 
Transmission  of  Power;  Measurement  of  Power,  Steam  Power;  Air  Power  Appliances;  Electric 
Power  and  Construction,  Navigation  and  Roads;  Gearing;  Motion  and  Devices;  Controlling 
Motion;  Horological;  Mining;  Mill  and  Factory  Appliances;  Construction  and  Devices; 
Drafting  Devices:  Miscellaneous  Devices,  etc.     12th  edition.      400  octavo  pages.     Price  $2.50 

MACHINE    SHOP    TOOLS    AND    SHOP    PRACTICE.      By  W.  H.  Vandervoort. 

A  work  of  555  pages  and  673  illustrations,  describing  in  every  detail  the  construction,  operation, 
and  manipulation  of  both  hand  and  machine  tools.  Includes  chapters  on  filing,  fitting,  and 
scraping  surfaces;  on  drills,  reamers,  taps,  and  dies;  the  lathe  and  its  tools;  planers,  shapers, 
and  their  tools:  milling  machines  and  cutters;  gear  cutters  and  gear  cutting;  drilling  machines 
and  drill  work;  grinding  machines  and  their  work;  hardening  and  tempering;  gearing,  belting 
and  transmission  machinery:    useful  data  and  tables.     6th  edition.      Price     ....     $3.00 

THE    MODERN    MACHINIST.     By  John  T.  Usher. 

This  is  a  book  showing,  by  plain  description  and  by  profuse  engravings,  made  expressly  for 
the  work,  all  that  is  best,  most  advanced,  and  of  the  highest  efficiency  in  modern  machine 
shop  practice,  tools,  and  implements,  showing  the  way  by  which  and  through  which,  as  Mr. 
Maxim  says,  "American  machinists  have  become  and  are  "the  finest  mechanics  in  the  world." 
Indicating  as  it  does,  in  every  line,  the  familiarity  of  the  author  with  every  detail  of  daily 
experience  in  the  shop,  it  cannot  fail  to  be  of  service  to  any  man  practically  -connected  with 
the  shaping  or  finishing  of  metals. 

There  is  nothing  experimental  or  visionary  about  the  book,  all  devices  being  in  actual  use 
and  giving  good  results.  It  might  be  called  a  compendium  of  shop  methods,  showing  a  vari- 
ety of  special  tools  and  appliances  which  will  give  new  ideas  to  many  mechanics,  from  the 
superintendent  down  to  the  man  at  the  bench.  It  will  be  found  a  valuable  addition  to  any 
machinist's  library,  and  should  be  consulted  whenever  a  new  or  difficult  job  is  to  be  done, 
whether  it  is  boring,  milling,  turning,  or  planing,  as  they  are  all  treated  in  a  practical  manner. 
Fifth  Edition.     320  pages.     250  illustrations.     Price      ...  $2.50 

MODERN  MILLING  MACHINES:  THEIR  DESIGN,  CONSTRUCTION  AND  OPERA- 
TION.    By  Joseph  G.  Horner. 

This  book  describes-and  illustrates  the  Milling  Machine  and  its  work  in  such  a  plain,  clear, 
and  forceful  manner,  and  illustrates  the  subject  so  clearly  and  completely,  that  the  up-to-date 
machinist,  student,  or  mechanical  engineer  cannot  afford  to  do  without  the  valuable  infor- 
mation which  it  contains.  It  describes  not  only  the  early  machines  of  this  class,  but  notes 
their  gradual  development  into  the  splendid  machines  of  the  present  day,  giving  the  design 
and  construction  of  the  various  types,  forms,  and  special  features  produced  by  prominent 
manufacturers,  American  and  foreign. 

Milling  cutters  in  all  their  development  and  modernized  forms  are  illustrated  and  described, 
and  the  operations  they  are  capable  of  producing  upon  different  classes  of  work  are  carefully 
described  in  detail,  and  the  speeds  and  feeds  necessary  are  discussed,  and  valuable  and  useful 
data  given  for  determining  these  usually  perplexing  problems.  The  book  is  the  most  compre- 
hensive work  published  on  the  subject.     304  pages.      300  illustrations.     Price       .     .     $4.00 

"  SHOP   KINKS."     By  Robert  Grimshaw. 

A  book  of  400  pages  and  222  illustrations,  being  entirely  different  frorn  any  other  book  on 
machine  shop  practice.  Departing  from  conventional  style,  the  author  avoids  universal  or 
common  shop  usage  and  limits  his  work  to  showing  special  ways  of  doing  things  better,  more 
cheaply  and  more  rapidly  than  usual.  As  a  result  the  advanced  methods  of  representative 
establishments  of  the  world  are  placed  at  the  disposal  of  the  reader.  This  book  shows  the 
proprietor  where  large  savings  are  possible,  and  how  products  may  be  improved.  To  the 
employee  it  holds  out  suggestions  that,  properly  applied,  will  hasten  his  advancement.  No 
shop  can  afford  to  be  without  it.  It  bristles  with  valuable  wrinkles  and  helpful  suggestions. 
It  will  benefit  all,  from  apprentice  to  proprietor.  Every  machinist,  at  any  age.  should  study 
its  pages.     Fifth  Edition.      Price $2.50 

21 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

THREADS  AND  THREAD  CUTTING.     By  Colvin  and  Stabel. 

This  clears  up  many  of  the  mysteries  of  thread-cutting,  such  as  double  and  triple  threads, 
internal  threads,  catching  threads,  use  of  hobs,  etc.  Contains  a  lot  of  useful  hints  and  several 
tables.     3rd  Edition.     Price 35  cents 

TOOLS  FOR  MACHINISTS  AND  WOOD  WORKERS,  INCLUDING  INSTRUMENTS 
OF   MEASUREMENT.     By  Joseph  G.  Horner. 

The  principles  upon  which  cutting  tools  for  wood,  metal,  and  other  substances  are  made  are 
identical,  whether  used  by  the  machinist,  the  carpenter,  or  by  any  other  skilled  mechanic  in 
their  daily  work,  and  the  object  of  this  book  is  to  give  a  correct  and  practical  description  of 
these  tools  as  they  are  commonly  designed,  constructed,  and  used.  340  pages,  fully  illustrated. 
Price $3.50 

MANUAL   TRAINING 


ECONOMICS    OF    MANUAL   TRAINING.     By  Louis  Rouillion. 

The  only  book  published  that  gives  just  the  information  needed  by  all  interested  in  .Manual 
Training,  regarding  Buildings,  Equipment,  and  Supplies.  Shows  exactly  what  is  needed  for 
all  grades  of  the  work  from  the  Kindergarten  to  the  High  and  Normal  School.  Gives  item- 
ized lists  of  everything  used  in  Manual  Training  Work  and  tells  just  what  it  ought  to  cost. 
Also  shows  where  to  buy  supplies,  etc.  Contains  174  pages,  and  is  fully  illustrated. 
2nd  Edition.      Price $1.50 

MARINE   ENGINEERING 


MARINE  ENGINES  AND  BOILERS,  THEIR  DESIGN  AND  CONSTRUCTION.  By 
Dr.  G.  Bauer,  Leslie  S.  Robertson,  and  S.  Bryan  Donkin. 

in  the  words  of  Dr.  Bauer,  the  present  work  owes  its  origin  to  an  oft  felt  want  of  a  Condensed 
Treatise,  embodying  the  Theoretical  and  Practical  Rules  used  in  Designing  Marine  Engines 
and  Boilers.  The  need  for  such  a  work  has  been  felt  by  most  engineers  engaged  in  the  con- 
struction and  working  of  Marine  Engines,  not  only  by  the  younger  men,  but  also  by  those  of 
greater  experience.  The  fact  that  the  original  German  work  was  written  by  the  chief  engineer 
of  the  famous  Vulcan  Works,  Stettin,  is  in  itself  a  guarantee  that  this  book  is  in  all  respects 
thoroughly  up-to-date,  and  that  it  embodies  all  the  information  which  is  necessary  for  the 
design  and  construction  of  the  highest  types  of  marine  engines  and  boilers.  It  may  be  said, 
that  the  motive  power  which  Dr.  Bauer  has  placed  in  the  fast  German  liners  that  have  been 
turned  out  of  late  years  from  the  Stettin  Works,  represent  the  very  best  practice  in  marine 
engineering  of  the  present  day. 

This  work  is  clearly  written,  thoroughly  systematic,  theoretically  sound;  while  the  character 
of  its  plans,  drawings,  tables,  and  statistics  is  without  reproach.  The  illustrations  are  care- 
ful reproductions  from  actual  working  drawings,  with  some  well-executed  photographic  views 
of  completed  engines  and  boilers.      744  pages.     550  illustrations  and  numerous,  tables. 

$9.00  net 
MODERN  SUBMARINE  CHART. 

A  cross-section  view,  showing  clearly  and  distinctly  all  the  interior  of  a  Submarine  of  the 
latest  type.  You  get  more  information  from  this  chart,  about  the  construction  and  operation 
of  a  Submarine,  than  in  any  other  way.  No  Details  omitted — everything  is  accurate  and  to 
scale.  It  is  absolutely  correct  in  every  detail,  having  been  approved  by  Naval  Engineers. 
All  the  machinery  and  devices  fitted  in  a  modern  Submarine  Boat  are  shown  and  to  make  the 
engraving  more  readily  understood  all  the  features  are  shown  in  operative  form  with  Officers 
and  Men  in  the  act  of  performing  the  duties  assigned  to  them  in  service  conditions.  This 
CHART  IS  REALLY  AN  ENCYCLOPEDIA  OP  A  SUBMARINE.  It  is  educational 
and  worth  many  times  its  cost.     Mailed  in  a  Tube  for 25  cents 

MINING 

ORE  DEPOSITS,  WITH  A  CHAPTER  ON   HINTS  TO    PROSPECTORS.     By  J.   P. 

Johnson 

This  book  gives  a  condensed  account  of  the  ore-deposits  at  present  known  in  South  Africa. 
It  is  also  intended  as  a  guide  to  the  prospector.  Only  an  elementary  knowledge  of  geology 
and  some  mining  experience  are  necessary  in  order  to  understand  this  work.  With  these 
qualifications,  it  will  materially  assist  one  in  his  search  for  metalliferous  mineral  occurrences 

22 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

and,  so  far  as  simple- ores  are  concerned,  should  enable  one  to  form  some  idea  of  the  possi- 
bilities of  any  he  may  find. 

Among  the  chapters  given  are:  Titaniferous  and  Chromiferous  Iron  Oxides — Nickel — Cop- 
per— Cobalt — Tin — Molybdenum — Tungsten — Lead — Mercury — Antimony — Iron — Hints  to 
Prospectors $2.00 

PHYSICS    AND    CHEMISTRY    OF   MINING.     By  T.  H.  Byrom. 

A  practical  work  for  the  use  of  all  preparing  for  examinations  in  mining  or  qualifying  for 
colliery  managers'  certificates.  The  aim  of  the  author  in  this  excellent  book  is  to  place  clearly 
before  the  reader  useful  and  authoritative  data  which  will  render  him  valuable  assistance  in 
his  studies.  The  only  work  of  its  kind  published.  The  information  incorporated  in  it  will 
prove  of  the  greatest  practical  utility  to  students,  mining  engineers,  collierv  managers  and 
all  others  who  are  specially  interested  in  the  present-day  treatment  of  mining  problems. 
Among  its  contents  are  chapters  on:  The  Atmosphere;  Laws  Relating  to  the  Behavior  of 
Gases;  The  Diffusion  of  Gases;  Composition  of  the  Atmosphere:  Sundrv  Constituents  of  the 
Atmosphere;  Water;  Carbon;  Fire-Damp;  Combustion;  Coal  Dust  and  Its  Action;  Ex- 
plosives; Composition  of  Various  Coals  and  Fuels;  Methods  of  Analysis  of  Coal;  Strata  Ad- 
joining the  Coal  Measures;  Magnetism  and  Electricity;  Appendix;  Useful  Tables,  etc  ; 
Miscellaneous  Questions.     160  pages.     Illustrated $2.00 

PRACTICAL    COAL    MINING.     By  T.  H.  Cockix. 

An  important  work,  containing  428  pages  and  213  illustrations,  complete  with  practical  de- 
tails, which  will  intuitively  impart  to  the  reader,  not  only  a  general  knowledge  of  the  princi- 
ples of  coal  mining,  but  also  considerable  insight  into  allied  subjects.  This  treatise  is  posi- 
tively up  to  date  in  every  instance,  and  should  be  in  the  hands  of  every  colliery  engineer 
geologist,  mine  operator,  superintendent,  foreman,  and  all  others  who  are  interested  in  or 
connected  with    the  industry.     2nd  Edition $2.50 

PATTERN  MAKING 


PRACTICAL  PATTERN  MAKING.     By  F.  W.  Barrows. 

This  is  a  very  complete  and  entirely  practical  treatise  on  the  subject  of  pattern  making,  illus- 
trating pattern  work  in  wood  and  metal.  From  its  pages  you  are  taught  just  what  you  should 
know  about  pattern  making.  It  contains  a  detailed  description  of  the  materials  used  by 
pattern  makers,  also  the  tools,  both  those  for  hand  use.  and  the  more  interesting  machine 
tools;  having  complete  chapters  on  the  band  saw.  The  Buzz  Saw.  and  the  Lathe.  Individual 
patterns  of  many  different  kinds  are  fully  illustrated  and  described,  and  the  mounting  of 
metal  patterns  on  plates  for  molding  machines  is  included. 

Rules,  Formulas  and  Tables  are  included,  containing  simple  and  original  methods  for  finding 
the  weight  of  castings,  both  from  the  pattern  itself  and  from  the  drawings.  This  section 
contains  some  new  and  practical  formulas,  which  will  be  found  very  useful  in  estimating 
weights,  with  the  accuracy  required  for  quotations  to  prospective  customers.  All  of  these 
rules  are  simple,  and  can  be  put  to  practical  use  by  the  ordinary,  every-day  man,  and  they 
have  been  proved  by  years  of  actual  use. 

Plain  rules  for  keeping  down  the  cost  of  patterns,  with  a  complete  system  for  checking  the 
cost  of  and  marking  the  patterns,  and  a  card  record  showing  what  the  pattern  is,  material 
used,  where  located  in  safe,  with  its  cost  and  date  of  production,  is  included.  The  book  closes 
with  an  original  and  practical  method  for  the  inventory  and  valuation  of  patterns.  Con- 
taining 326  pages  and  150  detailed  illustrations.    Price $2.00 

PERFUMERY 

HENLEY'S  TWENTIETH  CENTURY  BOOK  OF  RECEIPTS,  FORMULAS  AND  PRO- 
CESSES.    Edited  by  G.  D.  Hiscox. 

The  most  valuable  Techno-chemical  Receipt  Book  published.  Contains  over  10,000  practical 
receipts,  many  of  which  will  prove  of  special  value  to  the  perfumer,  a  mine  of  information,  up- 
to-date  in  every  respect.     Price,  Cloth,  $3.00;  half  morocco $4.00 

PERFUMES    AND    THEIR    PREPARATION.     By  G.  W.  Askinson,  Perfumer. 

A  comprehensive  treatise,  in  which  there  has  been  nothing  omitted  that  could  be  of  value 
to  the  Perfumer.  Complete  directions  for  making  handkerchief  perfumes,  smelling-salts, 
sachets,  fumigating  pastilles:  preparations  for  the  care  of  the  skin,  the  mouth,  the  hair,  cos- 
metics, hair  dyes  and  other  toilet  articles  are  given,  also  a  detailed  description  of  aromatic 
substances:  their  nature,  tests  of  purity,  and  wholesale  manufacture.  A  book  of  general, 
as  well  as  professional  interest,  meeting  the  wants  not  only  of  the  druggist  and  perfume  man- 
ufacturer, but  also  of  the  general  public.     Third  edition      312  pages.     Illustrated.     .    $3.00 

23 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 
PLUMBING 

MECHANICAL  DRAWING  FOR  PLUMBERS.  By  R.  M.  Starbuck. 
A  concise,  comprehensive  and  practical  treatise  on  the  subject  of  mechanical  drawing  in  its 
various  modern  applications  to  the  work  of  all  who  are  in  any  way  connected  with  *he 
plumbing  trade.  Nothing  will  so  help  the  plumber  in  estimating  and  in  explaining  work  to 
customers  and  workmen  as  a  knowledge  of  drawing,  and  to  the  workman  it  is  of  inestimable 
value  if  he  is  to  rise  above  his  position  to  positions  of  greater  responsibility.  Among  the 
chapters  contained  are:  1.  Value  to  plumber  of  knowledge  of  drawing;  tools  required 
and  their  use;  common  views  needed  in  mechanical  drawing.  2.  Perspective  versus  mechan- 
ical drawing  in  showing  plumbing  construction.  3.  Correct  and  incorrect  methods  in 
plumbing  drawing;  plan  and  elevation  explained.  3.  Floor  and  cellar  plans  and  elevation; 
scale  drawings;  use  of  triangles.  5.  Use  of  triangles;  drawing  of  fittings,  traps,  etc.  6. 
Drawing  plumbing  elevations  and  fittings.  7.  Instructions  in  drawing  plumbing  elevations. 
8.  The  drawing  of  plumbing  fixtures;  scale  drawings.  9.  Drawing  of  fixtures  and  fittings. 
10.  Inking  of  drawings.  11.  Shading  of  drawings.  12.  Shading  of  drawings.  13.  Sec- 
tional drawings;  drawing  of  threads.  14.  Plumbing  elevations  from  architect's  plan. 
15.  Elevations  of  separate  parts  of  the  plumbing  system.  16.  Elevations  from  architect'? 
plans.  17.  Drawing  of  detail  plumbing  connections.  18.  Architect's  plans  and  plumbing 
elevations  of  residence.  19.  Plumbing  elevations  of  residence  (continued) ;  plumbing  plans 
for  cottage.  20.  Plumbing  elevations;  roof  connections.  21.  Plans  and  plumbing  eleva- 
tions for  six-flat  building.  22.  Drawing  of  various  parts  of  the  plumbing  system;  use  of 
scales.  23.  Use  of  architect's  scales.  24.  Special  features  in  the  illustrations  of  country 
plumbing.  25.  Drawing  of  wrought  iron  piping,  valves,  radiators,  coils,  etc.  26.  Drawing 
of  piping  to  illustrate  heating  systems.     150  illustrations.    Price $1.50 

MODERN  PLUMBING  ILLUSTRATED.     By  R.  M.  Starbuck. 

This  book  represents  the  highest  standard  of  plumbing  work.  It  has  been  adopted  and  used 
as  a  reference  book  by  the  United  States  Government,  in  its  sanitary  work  in  Cuba,  Porto 
Rico,  and  the  Philippines,  and  by  the  principal  Boards  of  Health  of  the  United  States  and 
Canada. 

It  gives  connections,  sizes  and  working  data  for  all  fixtures  and  groups  of  fixtures.  It  is 
helpful  to  the  master  plumber  in  demonstrating  to  his  customers  and  in  figuring  work.  It 
gives  the  mechanic  and  student  quick  and  easy  access  to  the  best  modern  plumbing  practice. 
Suggestions  for  estimating  plumbing  construction  are  contained  in  its  pages.  This  book 
represents,  in  a  word,  the  latest  and  best  up-to-date  practice,  and  should  be  in  the  hands  of 
every  architect,  sanitary  engineer  and  plumber  who  wishes  to  keep  himself  up  to  the  minute 
on  this  important  feature  of  construction.  Contains  following  chapters,  each  illustrated 
with  a  full-page  plate:  Kitchen  sink,  laundry  tubs,  vegetable  wash  sink;  lavatories, 
pantry  sinks,  contents  of  marble  slabs;  bath  tub,  foot  and  sitz  bath,  shower  bath;  water 
closets,  venting  of  water  closets ;  low-down  water  closets,  water  closets  operated  by  flush 
valves,  water  closet  range;  slop  sink,  urinals,  the  bidet;  hotel  and  restaurant  sink,  grease 
trap;  refrigerators,  safe  wastes,  laundry  waste;  lines  of  refrigerators,  bar  sinks,  soda  foun- 
tain sinks;  horse  stall,  frost-proof  water  closets;  connections  for  S  traps,  venting;  con- 
nections for  drum  traps;  soil  pipe  connections;  supporting  of  soil  pipe;  main  trap  and 
fresh  air  inlet;  floor  drains  and  cellar  drains,  subsoil  drainage;  water  closets  and  floor 
connections ;  local  venting ;  connections  for  bath  rooms ;  connections  for  bath  rooms,  con- 
tinued; connections  for  bath  rooms,  continued;  connections  for  bath  rooms,  continued; 
examples  of  poor  practice;  roughing-work  ready  for  test;  testing  of  plumbing  system; 
method  of  continuous  venting ;  continuous  venting  for  two-floor  work ;  continuous  venting 
for  two  lines  of  fixtures  on  three  or  more  floors ;  continuous  venting  of  water  closets ;  plumb- 
ing for  cottage  house;  construction  for  cellar  piping;  plumbing  for  residence,  use  of  special 
fittings;  plumbing  for  two-flat  house;  plumbing  for  apartment  building:  plumbing  for 
double  apartment  building;  plumbing  for  office  building;  plumbing  for  public  toilet  rooms; 
plumbing  for  public  toilet  rooms,  continued;  plumbing  for  bath  establishment ;  plumbing 
for  engine  house,  factory  plumbing ;  automatic  flushing  for  schools,  factories,  etc. ;  use  of 
flushing  valves;  urinals  for  public  toilet  rooms;  the  Durham  system,  the  destruction  of 
pipes  by  electrolysis;  construction  of  work  without  use  of  lead;  Automatic  sewage  lift, 
automatic  sump  tank ;  country  plumbing ;  construction  of  cesspools ;  septic  tank  and  auto- 
matic sewage  siphon;  country  plumbing;  water  supply  for  country  house;  thawing  of 
water  mains  and  service  by  electricity;  double  boilers;  hot  water  supply  of  large  build- 
ings ;  automatic  control  of  hot  water  tank ;  suggestions  for  estimating  plumbing  construc- 
tion.    400  octavo   pages,   fully  illustrated  by  55  full-page  engravings.     Price     .     $4.00 

STANDARD  PRACTICAL  PLUMBING.     By  R.  M.  Starbuck. 

A  complete  practical  treatise  of  450  pages  covering  the  subject  of  Modern  Plumbing 
in  all  its  branches,  a  large  amount  of  space  being  devoted  to  a  very  complete  and  practical 
treatment  of  the  subject  of  Hot  Water  Supply  and  Circulation  and  Range  Boiler  Work. 
Its  thirty  chapters  include  about  every  phase  of  the  subject  one  can  think  of,  making  it 

24- 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


an  indispensable  work  to  the  master  plumber,  the  journeyman  plumber,  and  the  apprentice 
plumber,  containing  chapters  on:  the  plumber's  tools;  wiping  solder,  composition  and  use; 
joint  wiping;  lead  work;  traps;  siphonage  of  traps;  venting;  continuous  venting;  house 
sewer  and  sewer  connections;  house  drain;  soil  piping,  roughing;  main  trap  and  fresh  air 
inlet;  floor,  yard,  cellar  drains,  rain  leaders,  etc. ;  fixture  wastes:  water  closets ;  ventilation; 
improved  plumbing  connections;  residence  plumbing;  plumbing  for  hotels,  schools,  fac- 
tories, stables,  etc.;  modern  country  plumbing;  filtration  of  sewage  and  water  supply; 
hot  and  cold  supply;  range  boilers;  circulation;  circulating  pipes;  range  boiler  problems; 
hot  water  for  large  buildings;  water  lift  and  its  use;  multiple  connections  for  hot  water 
boilers;  heating  of  radiation  by  supply  system;  theory  for  the  plumber;  drawing  for  the 
plumber.     Fully  illustrated  by  347  engravings.     Price $3.00 

RECEIPT   BOOK 


HENLEY'S  TWENTIETH  CENTURY  BOOK  OF  RECEIPTS,  FORMULAS  AND  PRO- 
CESSES.     Edited  by  Gardner  D.  Hiscox. 

The  most  valuable  Techno-chemical  Receipt  Book  published,  including  over  10,000  selected 
scientific,  chemical,  technological,  and  practical  receipts  and  processes. 

This  is  the  most  complete  Book  of  Receipts  ever  published,  giving  thousands  of  receipts  for 
the  manufacturer  of  valuable  articles  for  everyday  use.  Hints,  Helps,  Practical  Ideas,  and 
Secret  Processes  are  revealed  within  its  pages.  It  covers  every  branch  of  the  useful  arts  and 
tells  thousands  of  ways  of  making  money  and  is  just  the  book  everyone  should  have  at  his 
command. 

Modern  in  its  treatment  of  every  subject  that  properly  falls  within  its  scope,  the  book  may 
truthfully  be  said  to  present  the  very  latest  formulas  to  be  found  in  the  arts  and  industries 
and  to  retain  those  processes  which  long  experience  has  proven  worthy  of  a  permanent  record. 
To  present  here  even  a  limited  number  of  the  subjects  which  find  a  place  in  this  valuable 
work  would  be  difficult.  Suffice  to  say  that  in  its  pages  will  be  found  matter  of  intense  in- 
terest and  immeasurable  practical  value  to  the  scientific  amateur  and  to  him  who  wishes  to 
obtain  a  knowledge  of  the  many  processes  used  in  the  arts,  trades  and  manufactures,  a 
knowledge  which  will  render  his  pursuits  more  instructive  and  remunerative.  Serving  as  a 
reference  book  to  the  small  and  large  manufacturer  and  suppplying  intelligent  seekers  with 
the  information  necessary  to  conduct  a  process,  the  work  will  be  foimd  of  inestimable  worth 
to  the  Metallurgist,  the  Photographer,  the  Perfumer,  the  Painter,  the  Manufacturer  of 
Glues,  Pastes,  Cements,  and  Mucilages,  the  Compounder  of  Alloys,  the  Cook,  the  Physician, 
the  Druggist,  the  Electrician,  the  Brewer,  the  Engineer,  the  Foundryman.  the  Machinist, 
the  Potter,  the  Tanner,  the  Confectioner,  the  Chiropodist,  the  Manicure.  *he  Manufacturer 
of  Chemical  Novelties  and  Toilet  Preparations,  the  Dyer,  the  Electroplater,  the  Enameler, 
the  Engraver,  the  Provisioner.  the  Glass  'Vorker,  the  Goldbeater,  the  Watchmaker,  the  Jew- 
eler, the  Hat  Maker,  the  Ink  Manufacturer,  the  Optician,  the  Farmer,  the  Dairyman,  the 
Paper  Maker,  the  Wood  and  Metal  Worker,  the  Chandler  and  Soap  Maker,  the  Veterinary 
Surgeon,  and  the  Technologist  in  general. 

A  mine  of  information,  and  up-to-date  in  every  respect.  A  book  which  will  prove  of  value 
to  EVERYONE,  as  it  covers  every  branch  of  the  Useful  Arts.     S00  pages.     Price    $3.00 

WHAT    IS    SAID    OF    THIS    BOOK: 


"  Your  Twentieth  Century  Book  of  Receipts,  Formulas  and  Processes  duly  received.  I  am 
glad  to  have  a  copy  of  it,  and  if  I  could  not  replace  it  money  couldn't  buy  it.  It  is  the  best 
thing  of  the  sort  I  ever  saw."  (Signed)  M.  E.  Trux. 

Sparta.  Wis. 
'There  are  few  persons  who  would  not  be  able  to  find  in  the  book  some  single  formula  that 
would  repay  several  times  the  cost  of. the  book." — Merchant's  Record  and  Show  Window. 

RUBBER 


RUBBER  HAND  STAMPS  AND  THE  MANIPULATION  OF  INDIA  RUBBER.  By 
T.  O'Conor  Sloane. 

This  book  gives  full  details  on  all  points,  treating  in  a  concise  and  simple  manner  the  elements 
of  nearly  everything  it  is  necessary  to  understand  for  a  commencement  in  anv  branch  of  the 
India  Rubber  Manufacture.  The  making  of  all  kinds  of  Rubber  Hand  Stamps.  Small  Articles 
of  India  Rubber,  U.  S.  Government  Composition,  Dating  Hand  Stamps,  the  Manipulation 
of  Sheet  Rubber,    Toy  Balloons.  India  Rubber  Solutions,  Cements,  Blackings,  Renovating 

2  5 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

Varnish,  and  Treatment  for  India  Rubber  Shoes,  etc.;  the  Hektograph  Stamp  Inks,  and 
Miscellaneous  Notes,  with  a  Short  Account  of  the  Discovery,  Collection,  and  Manufacture  of 
India  Rubber  are  set  forth  in  a  manner  designed  to  be  readily  understood,  the  explanations 
being  plain  and  simple.  Including  a  chapter  on  Rubber  Tire  Making  and  Vulcanizing;  also  u 
chapter  on  the  uses  of  rubber  in  Surgery  and  Dentistry.  Third  revised  and  enlarged  edition 
175  pages.  Illustrated $1.00 

SAWS 


SAW  FILINGS  AND  MANAGEMENT  OF  SAWS.     By  Robert  Grimshaw. 

A  practical  hand  book  on  filing,  gumming,  swaging,  hammering,  and  the  brazing  of  band  saws, 
the  speed,  work,  and  power  to  run  circular  saws,  etc.  A  handy  book  for  those  who  have  charge 
of  saws,  or  for  those  mechanics  who  do  their  own  filing,  as  it  deals  with  the  proper  shape  and 
pitches  of  saw  teeth  of  all  kinds  and  gives  many  useful  hints  and  rules  for  gumming,  yetting, 
and  filing,  and  is  a  practical  aid  to  those  who  use  saws  for  any  purpose.  New  edition,  revised 
and  enlarged.      Illustrated.      Price $1.00 

STEAM   ENGINEERING 

AMERICAN   STATIONARY   ENGINEERING.     By  W.  E.  Crane. 

This  book  begins  at  the  boiler  room  and  takes  in  the  whole  power  plant.  A  plain  talk  on 
every-day  work  about  engines,  boilers,  and  their  accessories.  It  is  not  intended  to  be  scien- 
tific or  mathematical.  All  formulas  are  in  simple  form  so  that  any  one  imderstanding  plain 
arithmetic  can  readily  understand  any  of  them.  The  author  has  made  this  the  most  prac- 
tical book  in  print ;  has  given  the  results  of  his  years  of  experience,  and  has  included  about 
all  that  has  to  do  with  an  engine  room  or  a  power  plant.  You  are  not  left  to  guess  at  a  single 
point.  You  are  shown  clearly  what  to  expect  under  the  various  conditions ;  how  to  secure 
the  best  results;  ways  of  preventing  "shut  downs"  and  repairs;  in  short,  all  that  goes  to 
make  up  the  requirements  of  a  good  engineer,  capable  of  taking  charge  of  a  plant.  It's  plain 
enough  for  practical  men  and  yet  of  value  to  those  high  in  the  profession. 
\  partial  list  of  contents  is:  The  boiler  room,  cleaning  boilers,  firing,  feeding;  pumps; 
jispection  and  repair;  chimneys,  sizes  and  cost;  piping;  mason  work:  foundations;  testing 
cement;  pile  driving;  engines,  slow  and  high  speed;  valves;  valve  setting;  Corliss  engines, 
setting  valves,  single  and  double  eccentric;  air  pumps  and  condensers;  different  types  of 
condensers;  water  needed;  lining  up;  pounds;  pins  not  square  in  crosshead  or  crank; 
engineers' tools;  pistons  and  piston  rings ;  bearing  metal;  hardened  copper ;  drip  pipes  from 
cylinder  jackets;  belts,  how  made,  care  of;  oils;  greases;  testing  lubricants;  rules  and 
tables,  including  steam  tables;  areas  of  segments;  squares  and  square  root;  cubes  and  cube 
root;  areas  and  circumferences  of  circles.  Notes  on:  Brick  work;  explosions;  pumps; 
pump  valves;  beaters,  economizers;  safety  valves ;  lap.  lead,  and  clearance.  Has  a  complete 
examination  for  a  license,  etc.,  etc.    Second  edition.    285  pages,    Illustrated.   Price    .  $2.00 

EMINENT   ENGINEERS.     By  Dwight  Goddard. 

Everyone  who  appreciates  the  effect  of  such  great  inventions  as  the  Steam  Engine,  Steamboat, 
Locomotive,  Sewing  Machine,  Steel  Working,  and  other  fundamental  discoveries,  is  interested 
in  knowing  a  little  about  the  men  who  made  them  and  their  achievements. 
Mr.  Goddard  has  selected  thirty-two  of  the  world's  engineers  who  have  contributed  most 
largely  to  the  advancement  of  our  civilization  by  mechanical  means,  giving  only  such  facts  as 
are  of  general  interest  and  in  a  way  which  appeals  to  all,  whether  mechanics  or  not.  280 
pages.     35  illustrations.     Price       $1.50 

ENGINE   RUNNER'S   CATECHISM.     By  Robert  Grimshaw. 

A  practical  treatise  for  the  stationary  engineer,  telling  how  to  erect,  adjust  and  run  the  prin- 
cipal steam  engines  in  use  in  the  United  States.  Describing  the  principal  features  of  various 
special  and  well-known  makes  of  engines:  Temper  Cut-off,  Shipping  and  Receiving  Founda- 
tions, Erecting  and  Starting,  Valve  Setting,  Care  and  Use,  Emergencies,  Erecting  and  Ad- 
justing Special  Engines. 

The  questions  asked  throughout  the  catechism  are  plain  and  to  the  point,  and  the  answers 
are  given  in  such  simple  language  as  to  be  readily  understood  by  anyone.  All  the  instructions 
given  are  complete  and  up-to-date;  and  they  are  written  in  a  popular  style,  without  any 
technicalities  or  mathematical  formula.  The'work  is  of  a  handy  size  for  the  pocket,  clearly 
and  well  printed,  nicely  bound,  and  profusely  illustrated.     To  young  engineers  this  catechism 

26 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 

will  be  of  great  value  especially  to  those  whu  may  be  preparing  to  go  forward  to  be  examined 
for  certificates  of  competency;  and  to  engineers  generally  it  will  be  of  no  little  service,  as  they 
will  find  in  this  volume  more  really  practical  and  useful  information  than  is  to  be  found  any- 
where else  within  a  like  compass.     387  pages.     Seventh  edition.     Price        ....     $2.00 

ENGINE  TESTS   AND   BOILER   EFFICIENCIES.     By  J.  Buchetti. 

This  work  fully  describes  and  illustrates  the  method  of  testing  the  power  of  steam  engines, 
turbines  and  explosive  motors.  The  properties  of  steam  and  the  evaporative  power  of  fuels. 
Combustion  of  fuel  and  chimney  draft;  with  formulas  explained  or  practically  computed 
255  pages,  179  illustrations $3.00 

HORSEPOWER  CHART. 

Shows  the  horsepower  of  any  stationary  engine  without  calculation.  No  matter  what  the 
cylinder  diameter  of  stroke;  the  steam  pressure  or  cut  off;  the  revolutions,  or  whether  con- 
densing or  non-condensing,  it's  all  there.  Easy  to  use,  accurate,  and  saves  time  and  calcu- 
lations.    Especially  useful  to  engineers  and  designers.         50  cents 

MODERN  STEAM  ENGINEERING  IN  THEORY  AND  PRACTICE.  By  Gardner 
D.  Hiscox. 

This  is  a  complete  and  practical  work  issued  for  Stationary  Engineers  and  firemen  dealing 
with  the  care  and  management  of  boilers,  engines,  pumps,  superheated  steam,  refrigerating 
machinery,  dynamos,  motors,  elevators,  air  compressors,  and  all  other  branches  with  which 
the  modern  engineer  must  be  familiar.  Nearly  200  questions  with  their  answers  on  steam 
and  electrical  engineering,  likely  to  be  asked  by  the  Examining  Board,  are  included. 
Among  the  chapters  are:  Historical;  steam  and  its  properties;  appliances  for  the  genera- 
tion of  steam;  types  of  boilers:  chimney  and  its  work;  heat  economy  of  the  feed  water; 
steam  pumps  and  their  work:  incrustation  and  its  work;  steam  above  atmospheric  pressure; 
flow  of  steam  from  nozzles:  superheated  steam  and  its  work;  adiabatic  expansion  of  steam; 
indicator  and  its  work;  steam  engine  proportions;  slide  valve  engines  and  valve  motion; 
Corliss  engine  and  its  valve  gear;  compound  engine  and  its  theory;  triple  and  multiple 
expansion  engine,  steam  turbine;  refrigeration;  elevators  and  their  management;  cost 
of  power;  steam  engine  troubles;  electric  power  and  electric  plants.  487  pages.  405  en- 
gravings.    Price $3.00 

STEAM   ENGINE    CATECHISM.     By  Robert  Grimshaw. 

This  unique  volume  of  413  pages  is  not  only  a  catechism  on  the  question  and  answer  princi- 
ple; but  it  contains  formulas  and  worked-oiA  answers  for  all  the  Steam  problems  that  apper- 
tain to  the  operation  and  management  of  the  Steam  Engine.  Illustrations  of  various  valves 
and  valve  gear  with  their  principles  of  operation  are  given.  Thirty-four  Tables  that  are 
indispensable  to  every  engineer  and  fireman  that  wishes  to  be  progressive  and  is  ambitious  to 
become  master  of  his  calling  are  within  its  pages.  It  is  a  most  valuable  instructor  in  the 
service  of  Steam  Engineering.  Leading  engineers  have  recommended  it  as  a  valuable  educa- 
tor for  the  beginner  as  well  as  a  reference  book  for  the  engineer.  It  is  thoroughly  indexed 
for  every  detail.'  Every  essential  question  on  the  Steam  Engine  with  its  answer  is  contained 
in  this  valuable  work.     Sixteenth  edition.     Price $2.00 

STEAM  ENGINEER'S  ARITHMETIC.     By  Colvin-Cheney. 

A  practical  pocket  book  for  the  steam  engineer.  Shows  how  to  work  the  problems  of  the 
engine  room  and  shows  "why."  Tells  how  to  figure  horse-power  of  engines  and  boilers;  area 
of  boilers;  has  tables  of  areas  and  circumferences;  steam  tables;  has  a  dictionary  of  engineering 
terms.  Puts  you  on  to  all  all  of  the  little  kinks  in  figuring  whatever  there  is  to  figure  around 
a  power  plant.  Tells  you  about  the  heat  unit;  absolute  zero;  adiabatic  expansion;  duty  of 
engines;  factor  of  safety;  and  1,001  other  things;  and  everything  is  plain  and  simple — not 
the  hardest  way  to  figure,  but  the  easiest.     2nd  Edition 50  cents 

STEAM    HEATING    AND    VENTILATION 


PRACTICAL   STEAM,  HOT-WATER   HEATING   AND  VENTILATION.      Bv  A.  G. 

King. 

This  book  is  the  standard  and  latest  work  published  on  the  subject  and  has  been  prepared  for 
the  use  of  all  engaged  in  the  business  of  steam,  hot  water  heating,  and  ventilation.  It  is  an 
original  and  exhaustive  work.  Tells  how  to  get  heating  contracts,  how  to  install  heating  and 
ventilating  apparatus,  the  best  business  methods  to  be  used,  with  "Tricks  of  the  Trade"  for 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


shoo  use.  Rules  and  data  for  estimating  radiation  and  cost  and  such  tables  and  information 
as  make  it  an  indispensable  work  for  everyone  interested  in  steam,  hot  water  heating,  and  venti- 
lation. It  describes  all  the  principal  systems  of  steam,  hot  water,  vacuum,  vapor,  and  vacuum- 
vapor  heating,  together  with  the  new  accelerated  systems  of  hot  water  circulation,  including 
chapters  on  up-to-date  methods  of  ventilation  and  the  fan  or  blower  system  of  heating  and 
ventilation.  Containing  chapters  on:  I.  Introduction.  II.  Heat.  III.  Evolution  of 
artificial  heating  apparatus.  IV.  Boiler  surface  and  settings.  V.  The  chimney  flue.  VI. 
Pipe  and  fittings.  VII.  Valves,  various  kinds.  VIII.  Forms  of  radiating  surfaces.  IX. 
Locating  of  radiating  surfaces.  X.  Estimating  radiation.  XI.  Steam-heating  apparatus. 
XII.  Exhaust-steam  heating.  XIII.  Hot-water  heating.  XIV.  Pressure  systems  of  hot- 
water  work.  XV.  Hot-water  appliances.  XVI.  Greenhouse  heating.  XVII.  Vacuum 
vapor  and  vacuum  exhaust  heating.  XVIII.  Miscellaneous  heating.  XIX.  Radiator  and 
pipe  connections.  XX.  Ventilation.  XXI.  Mechanical  ventilation  and  hot-blast  heating. 
XXII.  Steam  appliances.  XXIII.  District  heating.  XXIV.  Pipe  and  boiler  covering. 
XXV.  Temperature  regulation  and  heat  control.  XXVI.  Business  methods.  XXVII. 
Miscellaneous.  XXVIII.  Rules,  tables  and  useful  information.  367  pages.  300  detailed 
engravings.     Price $3.00 

STEAM  PIPES 

STEAM    PIPES.:  THEIR    DESIGN    AND    CONSTRUCTION.     By    Wm.  H.  Booth. 

The  work  is  well  illustrated  in  regard  to  pipe  joints,  expansion  offsets,  flexible  joints,  and 
self-contained  sliding  joints  for  taking  up  the  expansion  of  long  pipes.  In  fact,  the  chapters 
on  the  flow  of  steam  and  expansion  of  pipes  are  most  valuable  to  all  steam  fitters  and  users. 
The  pressure  strength  of  pipes  and  method  of  hanging  them  are  well  treated  and  illustrated. 
Valves  and  by-passes  are  fully  illustrated  and  described,  as  are  also  flange  joints  and  their 
proper  proportions,  exhaust  heads  and  separators.  One  of  the  most  valuable  chapters  is  that 
on  superheated  steam  and  the  saving  of  steam  by  insulation  with  the  various  kinds  of  felt- 
ing and  other  materials  with  comparison  tables  of  the  loss  of  heat  in  thermal  units  from  naked 
and  felted  steam  pipes.     Contains  187  pages.     Price      .     .     .    ". $2.00 

STEEL 

AMERICAN  STEEL  WORKER.     By  E.  R.  Markham. 

This  book  tells  how  to  select,  and  how  to  work,  temper,  harden,  and  anneal  steel  for  everything 
on  earth.  It  doesn't  tell  how  to  temper  one  class  of  tools  and  then  leave  the  treatment  of 
another  kind  of  tool  to  your  imagination  and  judgment,  but  it  gives  careful  instructions  for 
every  detail  of  every  tool,  whether  it  be  a  tap,  a  reamer  or  just  a  screw-driver.  It  tells  about 
the  tempering  of  small  watch  springs,  the  hardening  of  cutlery,  and  the  annealing  of  dies.  In 
fact  there  isn't  a  thing  that  a  steel  worker  would  want  to  know  that  isn't  included.  It  is  the 
standard  book  on  selecting,  hardening,  and  tempering  all  grades  of  steel.  Among  the 
chapter  headings  might  be  mentioned  the  following  subjects:  Introduction:  the  workman; 
steel;  methods  of  heating;  heating  tool  steel;  forging;  annealing;  hardening  baths;  baths 
for  hardening:  hardening  steel;  drawing  the  temper  after  hardening;  examples  of  hard- 
ening; pack  hardening;  case  hardening;  spring  tempering;  making  tools  of  machine  steel; 
special  steels:  steel  for  various  tools;  causes  of  trouble;  high  speed  steels,  etc.  366  pages. 
Very  fully  illustrated.     3rd  Edition.    Price $2.50 

HARDENING,  TEMPERING,  ANNEALING,  AND  FORGING  OF  STEEL.       By  J.  V. 

WOODWORTH. 

A  new  work  treating  in  a  clear,  concise  manner  all  modern  processes  for  the  heating,  annealing 
forging,  welding,  hardening,  and  tempering  of  steel,  making  it  a  book  of  great  practical  value 
to  the  metal-working  mechanic  in  general,  with  special  directions  for  the  successful  hardening 
and  tempering  of  all  steel  tools  used  in  the  arts,  including  milling  cutters,  taps,  thread  dies, 
reamers,  both  solid  and  shell,  hollow  mills,  punches  and  dies,  and  all  kinds  of  sheet  metal 
working  tools,  shear  blades,  saws,  fine  cutlery,  and  metal  cutting  tools  of  all  description,  as 
well  as  for  all  implements  of  steel  both  large  and  small.  In  this  work  the  simplest  and  most 
satisfactory  hardening  and  tempering  processes  are  given. 

The  uses  to  which  the  leading  brands  of  steel  may  be  adapted  are  concisely  presented,  and  their 
treatment  for  working  under  different  conditions  explained,  also  the  special  methods  for  the 
hardening  and  tempering  of  special  brands. 

A  chapter  devoted  to  the  different  processes  for  Case-hardening  is  also  included,  and  special 
reference  made  to  the  adoption  of  machinery  steel  for  tools  of  various  kinds.  4th  Edition,  288 
pages.     201  Illustrations.     Price        $2.50 

28 


CATALOGUE  OF  GOOD,  PRACTICAL  BOOKS 


TURBINES 

MARINE  STEAM  TURBINES.  By  Dr.  G.  Bauer  and  0.  Lasche,  Assisted  by 
E.  Ludwig  and  H.  Vogel.  Translated  from  the  German  and  edited  by  M.  G.  S. 
Swallow. 

This  work  forms  a  supplementary  volume  to  the  book  entitled  "Marine  Engines  and  Boilers." 
The  authors  of  this  book.  Dr.  G.  Bauer  and  O.  Lasche.  may  be  regarded  as  the  leading 
authorities  on  turbine  construction. 

The  book  is  essentially  practical  and  discusses  turbines  in  -which  the  full  expansion  of  steam 
passes  through  a  number  of  separate  turbines  arranged  for  driving  two  or  more  shafts,  as 
in  the  Parsons  system,  and  turbines  in  which  the  complete  expansion  of  steam  from  inlet 
to  exhaust  pressure  occurs  in  a  turbine  on  one  shaft,  as  in  the  case  of  the  Curtis  machines. 
It  will  enable  a  designer  to  carry  out  all  the  ordinary  calculations  necessary  for  the  con- 
struction of  steam  turbines,  hence  it  fills  a  want  which  is  hardly  met  by  larger  and  more 
theoretical  works. 

Numerous  tables,  curves  and  diagrams  will  be  found,  which  explain  with  remarkable  lucidity 
the  reason  why  turbine  blades  are  designed  as  they  are,  the  course  which  steam  takes  through 
turbines  of  various  types,  the  thermodynamics  of  steam  turbine  calculation,  the  influence 
of  vacuum  on  steam  consumption  of  steam  turbines,  etc.  In  a  word,  the  very  information 
which  a  designer  and  builder  of  steam  turbines  most  requires.  The  book  is  divided  into 
parts  as  follows:  1.  Introduction.  2.  General  remarks  on  the  design  of  a  turbine  installa- 
tion. 3.  The  calculation  of  steam  turbines.  4.  Turbine  design.  5.  Shafting  and  pro- 
pellers. 6.  Condensing  plant.  7.  Arrangement  of  turbines.  8.  General  remarks  on  the 
arrangement  of  steam  turbines  in  steamers.  9.  Turbine-driven  auxiliaries.  10.  Tables. 
Large  octavo.  214  pages.  Fully  illustrated  and  containing  18  tables.  Including  an  entropy 
chart.     Price,  net $3.50 

WATCH   MAKING 


WATCHMAKER'S    HANDBOOK.     By  Claudius  Sauxier. 

This  famous  work  has  now  reached  its  seventh  edition  and  there  is  no  work  issued  that  can 
compare  to  it  for  clearness  and  completeness.  It  contains  498  pages  and  is  intended  as  a 
workshop  companion  for  those  engaged  in  Watch-making  and  allied  Mechanical  Arts.  Nearly 
250  engravings  and  fourteen  plates  are  included.     Price    ...  ....     $3.00 


7?; 


University  of  California 

SOUTHERN  REGIONAL  LIBRARY  FACILITY 

405  Hilgard  Avenue,  Los  Angeles,  CA  90024-1388 

Return  this  material  to  the  library 

from  which  it  was  borrowed. 


win* 


Series  9482 


^  ooo 


